def __init__(<EOL>self, session, mention_classes, mention_spaces, matchers, parallelism=<NUM_LIT:1><EOL>):
super(MentionExtractor, self).__init__(<EOL>session,<EOL>MentionExtractorUDF,<EOL>parallelism=parallelism,<EOL>mention_classes=mention_classes,<EOL>mention_spaces=mention_spaces,<EOL>matchers=matchers,<EOL>)<EOL>arity = len(mention_classes)<EOL>if not all(<EOL>len(x) == arity for x in [mention_classes, mention_spaces, matchers]<EOL>):<EOL><INDENT>raise ValueError(<EOL>"<STR_LIT>"<EOL>)<EOL><DEDENT>self.mention_classes = mention_classes<EOL>
Initialize the MentionExtractor.