code: function (overlay) {
  
              var registered = false,
                  i,
                  n;
  
              if (overlay instanceof Overlay) {
  
                  overlay.cfg.addProperty("manager", { value: this } );
  
                  this._bindFocus(overlay);
                  this._bindBlur(overlay);
                  this._bindDestroy(overlay);
                  this._syncZIndex(overlay);
  
                  this.overlays.push(overlay);
                  this.bringToTop(overlay);
  
                  registered = true;
  
              } else if (overlay instanceof Array) {
  
                  for (i = 0, n = overlay.length; i < n; i++) {
                      registered = this.register(overlay[i]) || registered;
                  }
  
              }
  
              return registered;
          }
docs: Registers an Overlay or an array of Overlays with the manager. Upon
  registration, the Overlay receives functions for focus and blur,
  along with CustomEvents for each.
  
  @method register
  @param {Overlay} overlay  An Overlay to register with the manager.
  @param {Overlay[]} overlay  An array of Overlays to register with
  the manager.
  @return {boolean} true if any Overlays are registered.