docs: def flush_all(self) -> str:
          """
          
          :return:
          """
  
          # self.bytes_buffer.seek(0)
          # contents = self.bytes_buffer.read()
          # self.bytes_buffer.truncate(0)
          # self.bytes_buffer.seek(0)
  
          # if contents is None:
          #     return ''
  
          contents = self.bytes_buffer.getvalue()
          self.bytes_buffer.truncate(0)
          self.bytes_buffer.seek(0)
  
          return (
              ''
              if not contents else
              contents.decode(self.source_encoding)
          )