def cmp(other)
			if (!other.kind_of?(Mask32))
				raise ArgumentError, "Expected an Mask32 object for 'other' but got a #{other.class}."
			end
			if (self.prefix_len < other.prefix_len)
				return 1
			elsif (self.prefix_len > other.prefix_len)
				return -1
			end
			return 0
		end
def cmp(other)
			if (!other.kind_of?(Mask32))
				raise ArgumentError, "Expected an Mask32 object for 'other' but got a #{other.class}."
			end
			if (self.prefix_len < other.prefix_len)
				return 1
			elsif (self.prefix_len > other.prefix_len)
				return -1
			end
			return 0
		end
cmp compares equality with another Mask32. Return:
* 1 if this Mask128 is larger in capacity
* 0 if the two are equal
* -1 if this Mask128 is smaller in capacity