public void GetNames()
{
Context context = new Context();
context.DefineVariable("a");
context.DefineVariable("b");
context.DefineVariable("c");
var names = context.GetNames();
Assert.IsNotNull(names);
Assert.AreEqual(3, names.Count);
Assert.IsTrue(names.Contains("a"));
Assert.IsTrue(names.Contains("b"));
Assert.IsTrue(names.Contains("c"));
}