#region .ctor
static Pair() {
    theHashCode = typeof( Pair<TFirst, TSecond> ).AssemblyQualifiedName.GetHashCode();
    unchecked {
        theHashCode += typeof( TFirst ).AssemblyQualifiedName.GetHashCode();
        theHashCode += typeof( TSecond ).AssemblyQualifiedName.GetHashCode();
    }
}

protected Pair() : base() {
    myHashCode = theHashCode;
}
public Pair( TFirst first, TSecond second ) : this() {
    myFirst = first;
    mySecond = second;
    unchecked {
        if ( null != first ) {
            myHashCode += first.GetHashCode();
        }
        if ( null != second ) {
            myHashCode += second.GetHashCode();
        }
    }
}
#endregion .ctor