check whether the given expression , which consists of a call to this function , evaluates to a boolean . if the function can return different more than one type of value at evaluation-time , it must decide whether to cast the result to a boolean at this time . concode_field_sep PlaceHolder placeHolder concode_field_sep boolean isValid concode_elem_sep Object evaluate
boolean function ( FunctionCallExpression arg0 ) { return true ; }