Parameter validation using Contract

Parameters can be validated by using the Contract class.

Example:

private void Foo(object p_obj)
{
    // do the contract validation here.
    System.Diagnostics.Contracts.Contract.Requires<ArgumentNullException>(p_obj != null, "Object parameter cannot be null");

    // the rest of the method body would go here.
    int x = 0;
    x++;
}