`Validator.method_source` returns `""` for `property` and `cached_property`

[anmyachev]

An interesting detail is that source_file_def_line method takes into account these types of objects and correctly finds the source code of the functions wrapped in these properties.

numpydoc/numpydoc/validate.py

Lines 313 to 324 in e7c6baf

	def source_file_def_line(self):
	"""
	Number of line where the object is defined in its file.
	"""
	try:
	if isinstance(self.code_obj, property):
	sourcelines = self._getsourcelines(self.code_obj.fget)
	elif isinstance(self.code_obj, functools.cached_property):
	sourcelines = self._getsourcelines(self.code_obj.func)
	else:
	sourcelines = self._getsourcelines(self.code_obj)
	# getsourcelines will return the line of the first decorator found for the

[anmyachev]

Validator.name also doesn't work for functools.cached_property.