public void CanLogicalAnd()
{
var env = new StandardEnvironment();
Assert.AreEqual(null, env.And(null, null));
Assert.AreEqual(false, env.And(null, false));
Assert.AreEqual(null, env.And(null, true));
Assert.AreEqual(false, env.And(false, null));
Assert.AreEqual(false, env.And(false, false));
Assert.AreEqual(false, env.And(false, true));
Assert.AreEqual(null, env.And(true, null));
Assert.AreEqual(false, env.And(true, false));
Assert.AreEqual(true, env.And(true, true));
}