IContract.cs

public interface IContract<T>
    {
        IContract<T> Is<TT>();
        IContract<T> IsEqual<TT>(TT of) where TT : T,IEquatable<TT>;
        IContract<T> IsGreatherThan<TT>(TT of) where TT : T,IComparable;
        IContract<T> IsGreatherThanOrEqual<TT>(TT of) where TT :T, IComparable;
        IContract<T> IsLessThan<TT>(TT of) where TT : T,IComparable;
        IContract<T> IsLessThanOrEq<TT>(TT of) where TT : T,IComparable;
        IContract<T> IsNot<TT>();
        IContract<T> IsNotEqual<TT>(TT of) where TT : T,IEquatable<TT>;
        IContract<T> IsNotNull();
        IContract<T> IsNotTheSameOf(object of);
        IContract<T> IsNull();
        IContract<T> IsTheSameOf(object of);
        IContract<T> Meet(Expression<Predicate<T>> predicate);
    }