@Test
public void invokeParamSingleAndRange() {

    FunctionTestUtil.assertResult( startsFunction.invoke( "a",
            new RangeImpl( Range.RangeBoundary.CLOSED, "a", "f", Range.RangeBoundary.CLOSED )),
            Boolean.TRUE );
    FunctionTestUtil.assertResult( startsFunction.invoke( "f",
            new RangeImpl( Range.RangeBoundary.CLOSED, "a", "f", Range.RangeBoundary.CLOSED )),
            Boolean.FALSE );
    FunctionTestUtil.assertResult( startsFunction.invoke( "a",
            new RangeImpl( Range.RangeBoundary.OPEN, "a", "f", Range.RangeBoundary.CLOSED )),
            Boolean.FALSE );
    FunctionTestUtil.assertResult( startsFunction.invoke( "a",
            new RangeImpl( Range.RangeBoundary.CLOSED, "b", "f", Range.RangeBoundary.CLOSED )),
            Boolean.FALSE );
}