public FEELFnResult<Boolean> invoke(@ParameterName( "point1" ) Comparable point1, @ParameterName( "point2" ) Comparable point2) {
        if ( point1 == null ) {
            return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "point1", "cannot be null"));
        }
        if ( point2 == null ) {
            return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "point2", "cannot be null"));
        }
        try {
            boolean result = point1.compareTo( point2 ) < 0;
            return FEELFnResult.ofResult( result );
        } catch( Exception e ) {
            // points are not comparable
            return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "point1", "cannot be compared to point2"));
        }
    }
@Test
    void invokeParamSingles() {
        FunctionTestUtil.assertResult( beforeFunction.invoke( "a", "b" ), Boolean.TRUE );
        FunctionTestUtil.assertResult( beforeFunction.invoke( "a", "a" ), Boolean.FALSE );
        FunctionTestUtil.assertResult( beforeFunction.invoke( "b", "a" ), Boolean.FALSE );
        FunctionTestUtil.assertResult( beforeFunction.invoke( BigDecimal.valueOf(2), BigDecimal.valueOf(1) ), Boolean.FALSE );
        FunctionTestUtil.assertResult( beforeFunction.invoke( BigDecimal.valueOf(1), BigDecimal.valueOf(2) ), Boolean.TRUE );
        FunctionTestUtil.assertResult( beforeFunction.invoke( BigDecimal.valueOf(1), BigDecimal.valueOf(1) ), Boolean.FALSE );
    }