@Test(expected = ClassCastException.class)
    public void shouldThrowIfValueToMinusIsNotNumeric() {
        Operator.minus.apply("1", "1");
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/OperatorExceptionTest.java