21.
What is the purpose of the lazy method in Ruby enumerators?

22.
What does the slice_before method do in Ruby enumerators?

23.
What does the one? method do in Ruby enumerators?

24.
What is the purpose of the each_cons method in Ruby enumerators?

25.
What is the purpose of the cycle method in Ruby enumerators?

27.
What does the take_while method do in Ruby enumerators?

28.
What is the purpose of the with_index method in Ruby enumerators?

29.
What does the each_slice method do in Ruby enumerators?

30.
What does the grep_v method do in Ruby enumerators?