def to_json(self):
if self._embedding:<EOL><INDENT>warnings.warn('<STR_LIT>'<EOL>'<STR_LIT>'<EOL>'<STR_LIT>'<EOL>'<STR_LIT>')<EOL><DEDENT>vocab_dict = {}<EOL>vocab_dict['<STR_LIT>'] = self._idx_to_token<EOL>vocab_dict['<STR_LIT>'] = dict(self._token_to_idx)<EOL>vocab_dict['<STR_LIT>'] = self._reserved_tokens<EOL>vocab_dict['<STR_LIT>'] = self._unknown_token<EOL>vocab_dict['<STR_LIT>'] = self._padding_token<EOL>vocab_dict['<STR_LIT>'] = self._bos_token<EOL>vocab_dict['<STR_LIT>'] = self._eos_token<EOL>return json.dumps(vocab_dict)<EOL>
Serialize Vocab object to json string.

        This method does not serialize the underlying embedding.