Not able to cover mutation coverage for Remove Conditional Mutator

Question

this.var = StringUtils.isEmpty(arr[1]) ? null : Double.parseDouble(arr[1]);

The above line is being tested by 3 mutators

1. Negated conditional -> killed
2. removed conditional - replaced equality check with false -> killed
3. removed conditional - replaced equality check with true -> survived

I have written test cases for both null, empty values and also arr[1] with some test value

But even after that I'm not able to kill the mutator mentioned in point 3

I tried test case by adding test value inside arr[1] and one more test case where empty string is provided and did Assertions for both test cases, but it's not covering RemoveConditionalMutator_EQUAL_IF