code: def _write_headers(self, headers):
          
          if headers:
              for name in sorted(headers.keys()):
                  yield name.encode("ascii")
                  yield b': '
                  yield headers[name].encode("ascii")
                  yield CRLF
          yield CRLF
docs: Yields the HTTP header text for some content.
  
          Parameters
          ----------
          headers : dict
              The headers to yield