public void SizeTest()
{
un.function.Add(new VarTerm("key1"), new VarTerm("value1"));
un.function.Add(new VarTerm("key2"), new VarTerm("value2"));
un.function.Add(new VarTerm("key3"), new VarTerm("value3"));
int resultado = un.Size();
Assert.AreEqual(3, resultado);
}