@getter<EOL>def extract(input, **params):
EXTRACT_FIELD = '<STR_LIT>'<EOL>extract_params = params<EOL>extract_params.update({AccessParams.KEY_TYPE: AccessParams.TYPE_SINGLE})<EOL>return __extract(input, params)[params.get(EXTRACT_FIELD)]<EOL>
Extract field value from document
:param input:
:param params:
:return: