code: def convert_content(self, fpath: str) -> typing.Optional[dict]:
          
          try:
              loader = self.loader_cls(fpath)
          except UnsupportedExtensionError:
              return
  
          return loader.convert_content()
docs: Convert content of source file with loader, provided with
          `loader_cls` self attribute.
  
          Returns dict with converted content if loader class support source file
          extenstions, otherwise return nothing.