docs: function(id, constructor, superklass) {
  
      var mtor = function() {};
      mtor.prototype  = superklass.prototype;
  
      function OpalClass() {};
      OpalClass.prototype = new mtor();
  
      var klass = new OpalClass();
  
      klass._id         = unique_id++;
      klass._alloc      = constructor;
      klass._isClass    = true;
      klass._name       = id;
      klass._super      = superklass;
      klass.constructor = OpalClass;
      klass._methods    = [];
      klass.__inc__     = [];
      klass.__parent    = superklass;
      klass._proto      = constructor.prototype;
  
      constructor.prototype._klass = klass;
  
      Opal[id] = klass;
      Opal.constants.push(id);
  
      return klass;
    }