docs: function(spirit, prefix, plugin) {
  		Object.defineProperty(spirit, prefix, {
  			enumerable: true,
  			configurable: true,
  			get: function() {
  				return plugin;
  			},
  			set: function() {
  				throw new Error(
  					'The property name "' + prefix + '" is reserved for the ' +
  					plugin.$classname + ' and cannot be redefined.' // note about 'force'!
  				);
  			}
  		});
  	}