diff --git a/packages/grafana-schema/src/raw/composable/logs/panelcfg/x/LogsPanelCfg_types.gen.ts b/packages/grafana-schema/src/raw/composable/logs/panelcfg/x/LogsPanelCfg_types.gen.ts
index 5ec7f5e4314..250f6d83143 100644
--- a/packages/grafana-schema/src/raw/composable/logs/panelcfg/x/LogsPanelCfg_types.gen.ts
+++ b/packages/grafana-schema/src/raw/composable/logs/panelcfg/x/LogsPanelCfg_types.gen.ts
@@ -15,6 +15,14 @@ export const pluginVersion = "11.1.0-pre";
 export interface Options {
   dedupStrategy: common.LogsDedupStrategy;
   enableLogDetails: boolean;
+  isFilterLabelActive?: unknown;
+  /**
+   * TODO: figure out how to define callbacks
+   */
+  onClickFilterLabel?: unknown;
+  onClickFilterOutLabel?: unknown;
+  onClickFilterOutString?: unknown;
+  onClickFilterString?: unknown;
   prettifyLogMessage: boolean;
   showCommonLabels: boolean;
   showLabels: boolean;
diff --git a/public/app/features/explore/Explore.tsx b/public/app/features/explore/Explore.tsx
index a890bcf48c1..a7a31d5075b 100644
--- a/public/app/features/explore/Explore.tsx
+++ b/public/app/features/explore/Explore.tsx
@@ -188,8 +188,7 @@ export class Explore extends React.PureComponent<Props, ExploreState> {
 
   /**
    * Used by Logs details.
-   * Returns true if all queries have the filter, otherwise false.
-   * TODO: In the future, we would like to return active filters based the query that produced the log line.
+   * Returns true if the query identified by `refId` has a filter with the provided key and value.
    * @alpha
    */
   isFilterLabelActive = async (key: string, value: string | number, refId?: string) => {
@@ -235,14 +234,14 @@ export class Explore extends React.PureComponent<Props, ExploreState> {
   /**
    * Used by Logs Popover Menu.
    */
-  onClickFilterValue = (value: string | number, refId?: string) => {
+  onClickFilterString = (value: string | number, refId?: string) => {
     this.onModifyQueries({ type: 'ADD_STRING_FILTER', options: { value: value.toString() } }, refId);
   };
 
   /**
    * Used by Logs Popover Menu.
    */
-  onClickFilterOutValue = (value: string | number, refId?: string) => {
+  onClickFilterOutString = (value: string | number, refId?: string) => {
     this.onModifyQueries({ type: 'ADD_STRING_FILTER_OUT', options: { value: value.toString() } }, refId);
   };
 
@@ -437,8 +436,8 @@ export class Explore extends React.PureComponent<Props, ExploreState> {
           splitOpenFn={this.onSplitOpen('logs')}
           scrollElement={this.scrollElement}
           isFilterLabelActive={this.isFilterLabelActive}
-          onClickFilterValue={this.onClickFilterValue}
-          onClickFilterOutValue={this.onClickFilterOutValue}
+          onClickFilterString={this.onClickFilterString}
+          onClickFilterOutString={this.onClickFilterOutString}
         />
       </ContentOutlineItem>
     );
diff --git a/public/app/features/explore/Logs/Logs.tsx b/public/app/features/explore/Logs/Logs.tsx
index e49468555f5..3a912190381 100644
--- a/public/app/features/explore/Logs/Logs.tsx
+++ b/public/app/features/explore/Logs/Logs.tsx
@@ -109,8 +109,8 @@ interface Props extends Themeable2 {
   isFilterLabelActive?: (key: string, value: string, refId?: string) => Promise<boolean>;
   logsFrames?: DataFrame[];
   range: TimeRange;
-  onClickFilterValue?: (value: string, refId?: string) => void;
-  onClickFilterOutValue?: (value: string, refId?: string) => void;
+  onClickFilterString?: (value: string, refId?: string) => void;
+  onClickFilterOutString?: (value: string, refId?: string) => void;
   loadMoreLogs?(range: AbsoluteTimeRange): void;
 }
 
@@ -943,8 +943,8 @@ class UnthemedLogs extends PureComponent<Props, State> {
                     scrollIntoView={this.scrollIntoView}
                     isFilterLabelActive={this.props.isFilterLabelActive}
                     containerRendered={!!this.state.logsContainer}
-                    onClickFilterValue={this.props.onClickFilterValue}
-                    onClickFilterOutValue={this.props.onClickFilterOutValue}
+                    onClickFilterString={this.props.onClickFilterString}
+                    onClickFilterOutString={this.props.onClickFilterOutString}
                   />
                 </InfiniteScroll>
               </div>
diff --git a/public/app/features/explore/Logs/LogsContainer.tsx b/public/app/features/explore/Logs/LogsContainer.tsx
index 48a173cd064..528daafa093 100644
--- a/public/app/features/explore/Logs/LogsContainer.tsx
+++ b/public/app/features/explore/Logs/LogsContainer.tsx
@@ -58,8 +58,8 @@ interface LogsContainerProps extends PropsFromRedux {
   splitOpenFn: SplitOpen;
   scrollElement?: HTMLDivElement;
   isFilterLabelActive: (key: string, value: string, refId?: string) => Promise<boolean>;
-  onClickFilterValue: (value: string, refId?: string) => void;
-  onClickFilterOutValue: (value: string, refId?: string) => void;
+  onClickFilterString: (value: string, refId?: string) => void;
+  onClickFilterOutString: (value: string, refId?: string) => void;
 }
 
 type DataSourceInstance =
@@ -350,8 +350,8 @@ class LogsContainer extends PureComponent<LogsContainerProps, LogsContainerState
             scrollElement={scrollElement}
             isFilterLabelActive={this.logDetailsFilterAvailable() ? this.props.isFilterLabelActive : undefined}
             range={range}
-            onClickFilterValue={this.filterValueAvailable() ? this.props.onClickFilterValue : undefined}
-            onClickFilterOutValue={this.filterOutValueAvailable() ? this.props.onClickFilterOutValue : undefined}
+            onClickFilterString={this.filterValueAvailable() ? this.props.onClickFilterString : undefined}
+            onClickFilterOutString={this.filterOutValueAvailable() ? this.props.onClickFilterOutString : undefined}
           />
         </LogsCrossFadeTransition>
       </>
diff --git a/public/app/features/explore/Logs/PopoverMenu.test.tsx b/public/app/features/explore/Logs/PopoverMenu.test.tsx
index 879e9fc0be5..81b9371526a 100644
--- a/public/app/features/explore/Logs/PopoverMenu.test.tsx
+++ b/public/app/features/explore/Logs/PopoverMenu.test.tsx
@@ -15,9 +15,9 @@ test('Does not render if the filter functions are not defined', () => {
 });
 
 test('Renders copy and line contains filter', async () => {
-  const onClickFilterValue = jest.fn();
+  const onClickFilterString = jest.fn();
   render(
-    <PopoverMenu selection="test" x={0} y={0} row={row} close={() => {}} onClickFilterValue={onClickFilterValue} />
+    <PopoverMenu selection="test" x={0} y={0} row={row} close={() => {}} onClickFilterString={onClickFilterString} />
   );
 
   expect(screen.getByText('Copy selection')).toBeInTheDocument();
@@ -25,12 +25,12 @@ test('Renders copy and line contains filter', async () => {
 
   await userEvent.click(screen.getByText('Add as line contains filter'));
 
-  expect(onClickFilterValue).toHaveBeenCalledTimes(1);
-  expect(onClickFilterValue).toHaveBeenCalledWith('test', row.dataFrame.refId);
+  expect(onClickFilterString).toHaveBeenCalledTimes(1);
+  expect(onClickFilterString).toHaveBeenCalledWith('test', row.dataFrame.refId);
 });
 
 test('Renders copy and line does not contain filter', async () => {
-  const onClickFilterOutValue = jest.fn();
+  const onClickFilterOutString = jest.fn();
   render(
     <PopoverMenu
       selection="test"
@@ -38,7 +38,7 @@ test('Renders copy and line does not contain filter', async () => {
       y={0}
       row={row}
       close={() => {}}
-      onClickFilterOutValue={onClickFilterOutValue}
+      onClickFilterOutString={onClickFilterOutString}
     />
   );
 
@@ -47,8 +47,8 @@ test('Renders copy and line does not contain filter', async () => {
 
   await userEvent.click(screen.getByText('Add as line does not contain filter'));
 
-  expect(onClickFilterOutValue).toHaveBeenCalledTimes(1);
-  expect(onClickFilterOutValue).toHaveBeenCalledWith('test', row.dataFrame.refId);
+  expect(onClickFilterOutString).toHaveBeenCalledTimes(1);
+  expect(onClickFilterOutString).toHaveBeenCalledWith('test', row.dataFrame.refId);
 });
 
 test('Renders copy, line contains filter, and line does not contain filter', () => {
@@ -59,8 +59,8 @@ test('Renders copy, line contains filter, and line does not contain filter', ()
       y={0}
       row={row}
       close={() => {}}
-      onClickFilterValue={() => {}}
-      onClickFilterOutValue={() => {}}
+      onClickFilterString={() => {}}
+      onClickFilterOutString={() => {}}
     />
   );
 
@@ -78,8 +78,8 @@ test('Can be dismissed with escape', async () => {
       y={0}
       row={row}
       close={close}
-      onClickFilterValue={() => {}}
-      onClickFilterOutValue={() => {}}
+      onClickFilterString={() => {}}
+      onClickFilterOutString={() => {}}
     />
   );
 
diff --git a/public/app/features/explore/Logs/PopoverMenu.tsx b/public/app/features/explore/Logs/PopoverMenu.tsx
index fe62668307c..6bc0265145c 100644
--- a/public/app/features/explore/Logs/PopoverMenu.tsx
+++ b/public/app/features/explore/Logs/PopoverMenu.tsx
@@ -11,8 +11,8 @@ interface PopoverMenuProps {
   selection: string;
   x: number;
   y: number;
-  onClickFilterValue?: (value: string, refId?: string) => void;
-  onClickFilterOutValue?: (value: string, refId?: string) => void;
+  onClickFilterString?: (value: string, refId?: string) => void;
+  onClickFilterOutString?: (value: string, refId?: string) => void;
   row: LogRowModel;
   close: () => void;
 }
@@ -20,8 +20,8 @@ interface PopoverMenuProps {
 export const PopoverMenu = ({
   x,
   y,
-  onClickFilterValue,
-  onClickFilterOutValue,
+  onClickFilterString,
+  onClickFilterOutString,
   selection,
   row,
   close,
@@ -42,7 +42,7 @@ export const PopoverMenu = ({
     };
   }, [close]);
 
-  const supported = onClickFilterValue || onClickFilterOutValue;
+  const supported = onClickFilterString || onClickFilterOutString;
 
   if (!supported) {
     return null;
@@ -59,21 +59,21 @@ export const PopoverMenu = ({
             track('copy', selection.length, row.datasourceType);
           }}
         />
-        {onClickFilterValue && (
+        {onClickFilterString && (
           <Menu.Item
             label="Add as line contains filter"
             onClick={() => {
-              onClickFilterValue(selection, row.dataFrame.refId);
+              onClickFilterString(selection, row.dataFrame.refId);
               close();
               track('line_contains', selection.length, row.datasourceType);
             }}
           />
         )}
-        {onClickFilterOutValue && (
+        {onClickFilterOutString && (
           <Menu.Item
             label="Add as line does not contain filter"
             onClick={() => {
-              onClickFilterOutValue(selection, row.dataFrame.refId);
+              onClickFilterOutString(selection, row.dataFrame.refId);
               close();
               track('line_does_not_contain', selection.length, row.datasourceType);
             }}
diff --git a/public/app/features/logs/components/LogRows.test.tsx b/public/app/features/logs/components/LogRows.test.tsx
index f412cb22cf7..5bf9fcb53da 100644
--- a/public/app/features/logs/components/LogRows.test.tsx
+++ b/public/app/features/logs/components/LogRows.test.tsx
@@ -221,8 +221,8 @@ describe('Popover menu', () => {
         logsSortOrder={LogsSortOrder.Descending}
         enableLogDetails={true}
         displayedFields={[]}
-        onClickFilterOutValue={() => {}}
-        onClickFilterValue={() => {}}
+        onClickFilterOutString={() => {}}
+        onClickFilterString={() => {}}
         app={app}
       />
     );
diff --git a/public/app/features/logs/components/LogRows.tsx b/public/app/features/logs/components/LogRows.tsx
index 3049d5ba9d7..400266137f4 100644
--- a/public/app/features/logs/components/LogRows.tsx
+++ b/public/app/features/logs/components/LogRows.tsx
@@ -68,8 +68,8 @@ export interface Props extends Themeable2 {
    * Any overflowing content will be clipped at the table boundary.
    */
   overflowingContent?: boolean;
-  onClickFilterValue?: (value: string, refId?: string) => void;
-  onClickFilterOutValue?: (value: string, refId?: string) => void;
+  onClickFilterString?: (value: string, refId?: string) => void;
+  onClickFilterOutString?: (value: string, refId?: string) => void;
 }
 
 interface State {
@@ -107,7 +107,7 @@ class UnThemedLogRows extends PureComponent<Props, State> {
     if (!config.featureToggles.logRowsPopoverMenu || this.props.app !== CoreApp.Explore) {
       return false;
     }
-    return Boolean(this.props.onClickFilterOutValue || this.props.onClickFilterValue);
+    return Boolean(this.props.onClickFilterOutString || this.props.onClickFilterString);
   }
 
   handleSelection = (e: MouseEvent<HTMLTableRowElement>, row: LogRowModel): boolean => {
@@ -217,8 +217,8 @@ class UnThemedLogRows extends PureComponent<Props, State> {
             row={this.state.selectedRow}
             selection={this.state.selection}
             {...this.state.popoverMenuCoordinates}
-            onClickFilterValue={rest.onClickFilterValue}
-            onClickFilterOutValue={rest.onClickFilterOutValue}
+            onClickFilterString={rest.onClickFilterString}
+            onClickFilterOutString={rest.onClickFilterOutString}
           />
         )}
         <table className={cx(styles.logsRowsTable, this.props.overflowingContent ? '' : styles.logsRowsTableContain)}>
diff --git a/public/app/plugins/panel/logs/LogsPanel.test.tsx b/public/app/plugins/panel/logs/LogsPanel.test.tsx
index 2230f70dae1..400423a8842 100644
--- a/public/app/plugins/panel/logs/LogsPanel.test.tsx
+++ b/public/app/plugins/panel/logs/LogsPanel.test.tsx
@@ -324,6 +324,63 @@ describe('LogsPanel', () => {
       expect(jest.mocked(styles.getLogRowStyles).mock.calls.length).toBeGreaterThan(3);
     });
   });
+
+  describe('Filters', () => {
+    const series = [
+      createDataFrame({
+        refId: 'A',
+        fields: [
+          {
+            name: 'time',
+            type: FieldType.time,
+            values: ['2019-04-26T09:28:11.352440161Z'],
+          },
+          {
+            name: 'message',
+            type: FieldType.string,
+            values: ['logline text'],
+            labels: {
+              app: 'common_app',
+            },
+          },
+        ],
+      }),
+    ];
+
+    it('allow to filter for a value or filter out a value', async () => {
+      const filterForMock = jest.fn();
+      const filterOutMock = jest.fn();
+      const isFilterLabelActiveMock = jest.fn();
+      setup({
+        data: {
+          series,
+        },
+        options: {
+          showLabels: false,
+          showTime: false,
+          wrapLogMessage: false,
+          showCommonLabels: false,
+          prettifyLogMessage: false,
+          sortOrder: LogsSortOrder.Descending,
+          dedupStrategy: LogsDedupStrategy.none,
+          enableLogDetails: true,
+          onClickFilterLabel: filterForMock,
+          onClickFilterOutLabel: filterOutMock,
+          isFilterLabelActive: isFilterLabelActiveMock,
+        },
+      });
+
+      expect(await screen.findByRole('row')).toBeInTheDocument();
+
+      await userEvent.click(screen.getByText('logline text'));
+      await userEvent.click(screen.getByLabelText('Filter for value in query A'));
+      expect(filterForMock).toHaveBeenCalledTimes(1);
+      await userEvent.click(screen.getByLabelText('Filter out value in query A'));
+      expect(filterOutMock).toHaveBeenCalledTimes(1);
+
+      expect(isFilterLabelActiveMock).toHaveBeenCalledTimes(1);
+    });
+  });
 });
 
 const setup = (propsOverrides?: {}) => {
diff --git a/public/app/plugins/panel/logs/LogsPanel.tsx b/public/app/plugins/panel/logs/LogsPanel.tsx
index 40aa8dab3f0..0bafecd0004 100644
--- a/public/app/plugins/panel/logs/LogsPanel.tsx
+++ b/public/app/plugins/panel/logs/LogsPanel.tsx
@@ -29,10 +29,34 @@ import { LogLabels } from '../../../features/logs/components/LogLabels';
 import { LogRows } from '../../../features/logs/components/LogRows';
 import { COMMON_LABELS, dataFrameToLogsModel, dedupLogRows } from '../../../features/logs/logsModel';
 
-import { Options } from './types';
+import {
+  isIsFilterLabelActive,
+  isOnClickFilterLabel,
+  isOnClickFilterOutLabel,
+  isOnClickFilterOutString,
+  isOnClickFilterString,
+  Options,
+} from './types';
 import { useDatasourcesFromTargets } from './useDatasourcesFromTargets';
 
-interface LogsPanelProps extends PanelProps<Options> {}
+interface LogsPanelProps extends PanelProps<Options> {
+  /**
+   * Adds a key => value filter to the query referenced by the provided DataFrame refId. Used by Log details and Logs table.
+   * onClickFilterLabel?: (key: string, value: string, frame?: DataFrame) => void;
+   *
+   * Adds a negative key => value filter to the query referenced by the provided DataFrame refId. Used by Log details and Logs table.
+   * onClickFilterOutLabel?: (key: string, value: string, frame?: DataFrame) => void;
+   *
+   * Adds a string filter to the query referenced by the provided DataFrame refId. Used by the Logs popover menu.
+   * onClickFilterOutString?: (value: string, refId?: string) => void;
+   *
+   * Removes a string filter to the query referenced by the provided DataFrame refId. Used by the Logs popover menu.
+   * onClickFilterString?: (value: string, refId?: string) => void;
+   *
+   * Determines if a given key => value filter is active in a given query. Used by Log details.
+   * isFilterLabelActive?: (key: string, value: string, refId?: string) => Promise<boolean>;
+   */
+}
 interface LogsPermalinkUrlState {
   logs?: {
     id?: string;
@@ -55,6 +79,11 @@ export const LogsPanel = ({
     dedupStrategy,
     enableLogDetails,
     showLogContextToggle,
+    onClickFilterLabel,
+    onClickFilterOutLabel,
+    onClickFilterOutString,
+    onClickFilterString,
+    isFilterLabelActive,
   },
   id,
 }: LogsPanelProps) => {
@@ -68,7 +97,7 @@ export const LogsPanel = ({
   const [scrollElement, setScrollElement] = useState<HTMLDivElement | null>(null);
   let closeCallback = useRef<() => void>();
 
-  const { eventBus } = usePanelContext();
+  const { eventBus, onAddAdHocFilter } = usePanelContext();
   const onLogRowHover = useCallback(
     (row?: LogRowModel) => {
       if (!row) {
@@ -220,6 +249,28 @@ export const LogsPanel = ({
     [scrollElement]
   );
 
+  const defaultOnClickFilterLabel = useCallback(
+    (key: string, value: string) => {
+      onAddAdHocFilter?.({
+        key,
+        value,
+        operator: '=',
+      });
+    },
+    [onAddAdHocFilter]
+  );
+
+  const defaultOnClickFilterOutLabel = useCallback(
+    (key: string, value: string) => {
+      onAddAdHocFilter?.({
+        key,
+        value,
+        operator: '!=',
+      });
+    },
+    [onAddAdHocFilter]
+  );
+
   if (!data || logRows.length === 0) {
     return <PanelDataErrorView fieldConfig={fieldConfig} panelId={id} data={data} needsStringField />;
   }
@@ -275,6 +326,17 @@ export const LogsPanel = ({
             onLogRowHover={onLogRowHover}
             app={CoreApp.Dashboard}
             onOpenContext={onOpenContext}
+            onClickFilterLabel={
+              isOnClickFilterLabel(onClickFilterLabel) ? onClickFilterLabel : defaultOnClickFilterLabel
+            }
+            onClickFilterOutLabel={
+              isOnClickFilterOutLabel(onClickFilterOutLabel) ? onClickFilterOutLabel : defaultOnClickFilterOutLabel
+            }
+            onClickFilterString={isOnClickFilterString(onClickFilterString) ? onClickFilterString : undefined}
+            onClickFilterOutString={
+              isOnClickFilterOutString(onClickFilterOutString) ? onClickFilterOutString : undefined
+            }
+            isFilterLabelActive={isIsFilterLabelActive(isFilterLabelActive) ? isFilterLabelActive : undefined}
           />
           {showCommonLabels && isAscending && renderCommonLabels()}
         </div>
diff --git a/public/app/plugins/panel/logs/panelcfg.cue b/public/app/plugins/panel/logs/panelcfg.cue
index fd3719ec65c..481fb99efe6 100644
--- a/public/app/plugins/panel/logs/panelcfg.cue
+++ b/public/app/plugins/panel/logs/panelcfg.cue
@@ -26,15 +26,21 @@ composableKinds: PanelCfg: {
 			version: [0, 0]
 			schema: {
 				Options: {
-					showLabels:           bool
-					showCommonLabels:     bool
-					showTime:             bool
-					showLogContextToggle: bool
-					wrapLogMessage:       bool
-					prettifyLogMessage:   bool
-					enableLogDetails:     bool
-					sortOrder:            common.LogsSortOrder
-					dedupStrategy:        common.LogsDedupStrategy
+					showLabels:              bool
+					showCommonLabels:        bool
+					showTime:                bool
+					showLogContextToggle:    bool
+					wrapLogMessage:          bool
+					prettifyLogMessage:      bool
+					enableLogDetails:        bool
+					sortOrder:               common.LogsSortOrder
+					dedupStrategy:           common.LogsDedupStrategy
+					// TODO: figure out how to define callbacks
+					onClickFilterLabel?:     _
+					onClickFilterOutLabel?:  _
+					isFilterLabelActive?:    _
+					onClickFilterString?:    _
+					onClickFilterOutString?: _
 				} @cuetsy(kind="interface")
 			}
 		}]
diff --git a/public/app/plugins/panel/logs/panelcfg.gen.ts b/public/app/plugins/panel/logs/panelcfg.gen.ts
index 62e8fc956ed..c41589a2ce0 100644
--- a/public/app/plugins/panel/logs/panelcfg.gen.ts
+++ b/public/app/plugins/panel/logs/panelcfg.gen.ts
@@ -13,6 +13,14 @@ import * as common from '@grafana/schema';
 export interface Options {
   dedupStrategy: common.LogsDedupStrategy;
   enableLogDetails: boolean;
+  isFilterLabelActive?: unknown;
+  /**
+   * TODO: figure out how to define callbacks
+   */
+  onClickFilterLabel?: unknown;
+  onClickFilterOutLabel?: unknown;
+  onClickFilterOutString?: unknown;
+  onClickFilterString?: unknown;
   prettifyLogMessage: boolean;
   showCommonLabels: boolean;
   showLabels: boolean;
diff --git a/public/app/plugins/panel/logs/types.ts b/public/app/plugins/panel/logs/types.ts
index 1473f1fd934..711bd17c54f 100644
--- a/public/app/plugins/panel/logs/types.ts
+++ b/public/app/plugins/panel/logs/types.ts
@@ -1 +1,29 @@
+import { DataFrame } from '@grafana/data';
+
 export { Options } from './panelcfg.gen';
+
+type onClickFilterLabelType = (key: string, value: string, frame?: DataFrame) => void;
+type onClickFilterOutLabelType = (key: string, value: string, frame?: DataFrame) => void;
+type onClickFilterValueType = (value: string, refId?: string) => void;
+type onClickFilterOutStringType = (value: string, refId?: string) => void;
+type isFilterLabelActiveType = (key: string, value: string, refId?: string) => Promise<boolean>;
+
+export function isOnClickFilterLabel(callback: unknown): callback is onClickFilterLabelType {
+  return typeof callback === 'function';
+}
+
+export function isOnClickFilterOutLabel(callback: unknown): callback is onClickFilterOutLabelType {
+  return typeof callback === 'function';
+}
+
+export function isOnClickFilterString(callback: unknown): callback is onClickFilterValueType {
+  return typeof callback === 'function';
+}
+
+export function isOnClickFilterOutString(callback: unknown): callback is onClickFilterOutStringType {
+  return typeof callback === 'function';
+}
+
+export function isIsFilterLabelActive(callback: unknown): callback is isFilterLabelActiveType {
+  return typeof callback === 'function';
+}