code: function createBottomPanel(id, $panel, minSize) {
          $panel.insertBefore("#status-bar");
          $panel.hide();
          updateResizeLimits();  // initialize panel's max size
  
          panelIDMap[id] = new Panel($panel, minSize);
          panelIDMap[id].panelID = id;
  
          return panelIDMap[id];
      }
docs: Creates a new resizable panel beneath the editor area and above the status bar footer. Panel is initially invisible.
  The panel's size & visibility are automatically saved & restored as a view-state preference.
  
  @param {!string} id  Unique id for this panel. Use package-style naming, e.g. "myextension.feature.panelname"
  @param {!jQueryObject} $panel  DOM content to use as the panel. Need not be in the document yet. Must have an id
  attribute, for use as a preferences key.
  @param {number=} minSize  Minimum height of panel in px.
  @return {!Panel}