@Test(expected = ExprEvalException.class)
public void testExec_pos0_fail() {

    NodeValue v1 = NodeValue.makeString("10.0");
    NodeValue v2 = NodeValue.makeDouble(20.0);
    NodeValue v3 = NodeValue.makeDouble(10.0);
    NodeValue v4 = NodeValue.makeDouble(20.0001);
    NodeValue v5 = NodeValue.makeNode(NodeFactory.createURI(Unit_URI.KILOMETER_URL));
    GreatCircleFF instance = new GreatCircleFF();
    NodeValue expResult = NodeValue.makeDouble(20);
    NodeValue result = instance.exec(v1, v2, v3, v4, v5);
    assertEquals(expResult, result);
}