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

[Anatoly Myachev]

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 

[Anatoly Myachev]

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