demo/amd/rjs/output/unified/marionette-build.js
function() {
      var parent  = this._parent;
  
      while (parent) {
        if (parent instanceof Marionette.LayoutView) {
          return parent;
        }
        parent = parent._parent;
      }
    }
function() {
      var parent  = this._parent;
  
      while (parent) {
        if (parent instanceof Marionette.LayoutView) {
          return parent;
        }
        parent = parent._parent;
      }
    }
Walk the _parent tree until we find a layout view (if one exists). Returns the parent layout view hierarchically closest to this view.