src/extension.js
function( options ){
      this.options = options;

      registrant.call( this, options );

      // make sure layout has _private for use w/ std apis like .on()
      if( !is.plainObject( this._private ) ){
        this._private = {};
      }

      this._private.cy = options.cy;
      this._private.listeners = [];

      this.createEmitter();
    }
function( options ){
      this.options = options;

      registrant.call( this, options );

      // make sure layout has _private for use w/ std apis like .on()
      if( !is.plainObject( this._private ) ){
        this._private = {};
      }

      this._private.cy = options.cy;
      this._private.listeners = [];

      this.createEmitter();
    }
function ( options ) { this . options = options ; registrant . call ( this , options ) ; // make sure layout has _private for use w/ std apis like .on() if ( ! is . plainObject ( this . _private ) ) { this . _private = { } ; } this . _private . cy = options . cy ; this . _private . listeners = [ ] ; this . createEmitter ( ) ; }
fill in missing layout functions in the prototype
fill in missing layout functions in the prototype