I noticed that when you dump an expression that uses null safe operator, the returned string doesn't maintain the null safe operator.

> (new ExpressionLanguage())->parse('user?.foo', ['user'])->getNodes()->dump()
= "user.foo"

I would have expected user?.foo to be returned instead.

(I've also fixed some test data providers cases - getDumpData provider should only generate cases with 2 elements but some tests are including a third argument. So I went ahead and removed them)