def contains(ip)
			if (!ip.kind_of?(IPv6))
				raise ArgumentError, "Expected an IPv6 object for 'ip' but got a #{ip.class}."
			end
			if (@base.addr == ip.addr & @m128.mask)
				return true
			end
			return false
		end
def contains(ip)
			if (!ip.kind_of?(IPv6))
				raise ArgumentError, "Expected an IPv6 object for 'ip' but got a #{ip.class}."
			end
			if (@base.addr == ip.addr & @m128.mask)
				return true
			end
			return false
		end
contains returns true if the IPv6Net contains the IPv6