code: def patch(self, patch):
          
          # explicitly pick out the parts to update so we don't inadvertently
          # step on the model name or anything
          self._contents.update({
              'patch_path': patch.original_file_path,
              'description': patch.description,
              'columns': patch.columns,
              'docrefs': patch.docrefs,
          })
          # patches always trigger re-validation
          self.validate()
docs: Given a ParsedNodePatch, add the new information to the node.