public void Equals() { NegationExpression expr1 = new NegationExpression(new ConstantExpression(1)); NegationExpression expr2 = new NegationExpression(new ConstantExpression(2)); NegationExpression expr3 = new NegationExpression(new ConstantExpression(1)); 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)); }