question: @ Override public boolean mutate ( TestCase test , TestFactory factory ) { if ( Randomness . nextDouble ( ) >= Properties . P_CHANGE_PARAMETER ) return false ; if ( ! isStatic ( ) ) { VariableReference source = getSource ( ) ; List < VariableReference > objects = test . getObjects ( source . getType ( ) , getPosition ( ) ) ; objects . remove ( source ) ; if ( ! objects . isEmpty ( ) ) { setSource ( Randomness . choice ( objects ) ) ; return true ; } } return false ; }
target:  Try to replace source of field with all possible choices