Return doted-written address by the given WFQDN object

		:param address: address to convert
		:param leading_dot: whether this function place leading dot to the result or not
		:return: str

def to_string(address, leading_dot=False):
		""" Return doted-written address by the given WFQDN object

		:param address: address to convert
		:param leading_dot: whether this function place leading dot to the result or not
		:return: str
		"""

		if isinstance(address, WFQDN) is False:
			raise TypeError('Invalid type for FQDN address')

		result = '.'.join(address._labels)
		return result if leading_dot is False else (result + '.')