public void Equals()
{
AddExpression expr1 = new AddExpression(new ConstantExpression(1), new ConstantExpression(2));
AddExpression expr2 = new AddExpression(new ConstantExpression(1), new ConstantExpression(3));
AddExpression expr3 = new AddExpression(new ConstantExpression(1), new ConstantExpression(2));
AddExpression expr4 = new AddExpression(new ConstantExpression(2), new ConstantExpression(2));
Assert.IsTrue(expr1.Equals(expr3));
Assert.IsTrue(expr3.Equals(expr1));
Assert.AreEqual(expr1.GetHashCode(), expr3.GetHashCode());
Assert.IsFalse(expr1.Equals(null));
Assert.IsFalse(expr1.Equals("foo"));
Assert.IsFalse(expr1.Equals(expr2));
Assert.IsFalse(expr2.Equals(expr1));
Assert.IsFalse(expr1.Equals(expr4));
Assert.IsFalse(expr4.Equals(expr1));
}