code: async def write(self, writer: Any,
                      close_boundary: bool=True) -> None:
          
          if not self._parts:
              return
  
          for part, encoding, te_encoding in self._parts:
              await writer.write(b'--' + self._boundary + b'\r\n')
              await writer.write(part._binary_headers)
  
              if encoding or te_encoding:
                  w = MultipartPayloadWriter(writer)
                  if encoding:
                      w.enable_compression(encoding)
                  if te_encoding:
                      w.enable_encoding(te_encoding)
                  await part.write(w)  # type: ignore
                  await w.write_eof()
              else:
                  await part.write(writer)
  
              await writer.write(b'\r\n')
  
          if close_boundary:
              await writer.write(b'--' + self._boundary + b'--\r\n')
docs: Write body.