Refactored all() method
Refactored any() method
Refactored reject() method
Refactored any() for reusability
Refactored filter() method
Refactored compact() method
These methods don't belong here anymore
Refactored pick() method
Refactored find() method
Refactored values() method
Refactored keys() method
Refactored find() method
Refactored flatten() method
Refactored groupBy() method
Refactored tap() method
Refactored sortBy() method
Refactored head() method
Refactored last() method
Refactored tail() method
Refactored initial() method