def set_custom_boundary(doc):
if doc.user_data == {}:<EOL><INDENT>raise AttributeError("<STR_LIT>")<EOL><DEDENT>for token_nr, token in enumerate(doc):<EOL><INDENT>doc[token_nr].is_sent_start = False<EOL><DEDENT>token_nr = <NUM_LIT:0><EOL>for sentence in doc.user_data:<EOL><INDENT>doc[token_nr].is_sent_start = True<EOL>token_nr += len(sentence.words)<EOL><DEDENT>return doc<EOL>
Set the sentence boundaries based on the already separated sentences.
    :param doc: doc.user_data should have a list of Sentence.
    :return doc: