function Message(properties) {
    // not used internally
    if (properties)
        for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
            this[keys[i]] = properties[keys[i]];
}
Constructs a new message instance.
@classdesc Abstract runtime message.
@constructor
@param {Properties<T>} [properties] Properties to set
@template T extends object