Returns true if all the elements in the parameter list are included in the list.

Returns true if all element of *c2* are contained in self, false otherwise.

Expression	Result
Sequence{2.3, 5.2, 'a', 3, null}->includesAll(Set{3, null})	true
Sequence{2.3, 5.2, 'a', 3}->includesAll(Set{3, null})	false