class ColourableSquare (Colourable)
{
    constructors {
       size_constructor { params { @in int size; } }
    };
    legacy_prefix: legacy;
    properties {
        size {
            values {
                int size;
            };
            set {
                /*@ Sets size. */
            };
            get {
                /*@ Gets size. */
            };
        };
    };
    methods {
        size_print { /*@ Show the square. */ };
    };
};