Implement pending test on sample value generation for non case class type
fix erroneous expectations for test on Sequences
Fix erroneous expectations for multi-value function definition
Add mutability on SamplePool

This greatly simplifies the implementation and implements certain test cases that were to annoying to implement immutably.
After feedback, modified expectation of a test case
Minor fix in test case expectation

Remove the extra newLine
Add pending test for import support
Get rid of useless AST expression in anonymous class expressions
Correctly implementing function definitions in anonymous classes