code: def write_file(self, name, fp_src, blocksize=DEFAULT_BLOCKSIZE, callback=None):
          
          # print("FTP write_file({})".format(name), blocksize)
          assert compat.is_native(name)
          self.check_write(name)
          self.ftp.storbinary("STOR {}".format(name), fp_src, blocksize, callback)
docs: Write file-like `fp_src` to cur_dir/name.
  
          Args:
              name (str): file name, located in self.curdir
              fp_src (file-like): must support read() method
              blocksize (int, optional):
              callback (function, optional):
                  Called like `func(buf)` for every written chunk