Compress method doesn't remove all whitespaces

[Person-93]

I have a QueryBuilder class that I am testing and I tried to use the compress method on the actual and expected results before comparing them, but the tests fail because the whitespaces don't match.
This is the output from PHPUnit:
The filter text does not match the expected result. Failed asserting that two strings are equal. Expected :'someField = 1' Actual :'someField=1'