When you use a math expression with out any operators, the dataFrame pointer is identical between the expression result and the input query/expression.
This was resulting in the values returned from an evaluation overshadowing each other, depending on the order of the processing of the result map.
For example:
```
A: some_metric
B: reduce of A
C: math expression -> "${B}"
D: Threshold evaluation of C -> "C > 0"
```
With a value of 1 for `some_metric`, might result in a evaluation result of one of the following (somewhat at random):
1. { B: 1, D: 1 }
2. { C: 1, D: 1}
While you would expect to see:
{ B: 1, C: 1, D: 1 }
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