@Test
public 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 );
}