module Hamster::Enumerable

def <=>(other)
  return 0 if self.equal?(other)
  enum1, enum2 = self.to_enum, other.to_enum
  loop do
    item1 = enum1.next
    item2 = enum2.next
    comp  = (item1 <=> item2)
    return comp if comp != 0
  end
  size1, size2 = self.size, other.size
  return 0 if size1 == size2
  size1 > size2 ? 1 : -1
end