class Entity(object):
	def __init__(self, data, source_string=None):
		self.data = data
		if source_string is None:
			source_string = str(data)
		self.source_string = source_string

	@property
	def type(self):
	    return self.__class__.__name__


class DateTime(Entity):
	pass


class Email(Entity):
	pass


class Url(Entity):
	pass


class PhoneNumber(Entity):
	pass


class Number(Entity):
	pass