question: private FilterOperation extractOperation ( Matcher tokenizedQuery ) throws BadFilterException { String operationName = tokenizedQuery . group ( 2 ) ; try { return FilterOperation . valueOf ( operationName ) ; } catch ( IllegalArgumentException ignored ) { LOG . debug ( FILTER_OPERATOR_INVALID . logFormat ( operationName ) ) ; throw new BadFilterException ( FILTER_OPERATOR_INVALID . format ( operationName ) ) ; } }
target:  Extracts the operation to be performed by the ApiJobStore filter query.