<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def text_search(conn, search, *, language='english', case_sensitive=False, diacritic_sensitive=False, text_score=False, limit=0, table=None):
 """Return all the assets that match the text search. The results are sorted by text score. For more information about the behavior of text search on MongoDB see https://docs.mongodb.com/manual/reference/operator/query/text/#behavior Args: search (str):
 Text search string to query the text index language (str, optional):
 The language for the search and the rules for stemmer and tokenizer. If the language is ``None`` text search uses simple tokenization and no stemming. case_sensitive (bool, optional):
 Enable or disable case sensitive search. diacritic_sensitive (bool, optional):
 Enable or disable case sensitive diacritic search. text_score (bool, optional):
 If ``True`` returns the text score with each document. limit (int, optional):
 Limit the number of returned documents. Returns: :obj:`list` of :obj:`dict`: a list of assets Raises: OperationError: If the backend does not support text search """


    raise OperationError('This query is only supported when running '
                         'BigchainDB with MongoDB as the backend.')