code: def FindFileContainingSymbol(self, symbol):
      
  
      symbol = _NormalizeFullyQualifiedName(symbol)
      try:
        return self._descriptors[symbol].file
      except KeyError:
        pass
  
      try:
        return self._enum_descriptors[symbol].file
      except KeyError:
        pass
  
      try:
        file_proto = self._internal_db.FindFileContainingSymbol(symbol)
      except KeyError as error:
        if self._descriptor_db:
          file_proto = self._descriptor_db.FindFileContainingSymbol(symbol)
        else:
          raise error
      if not file_proto:
        raise KeyError('Cannot find a file containing %s' % symbol)
      return self._ConvertFileProtoToFileDescriptor(file_proto)
docs: Gets the FileDescriptor for the file containing the specified symbol.
  
      Args:
        symbol: The name of the symbol to search for.
  
      Returns:
        A FileDescriptor that contains the specified symbol.
  
      Raises:
        KeyError: if the file can not be found in the pool.