title: Drag and drop between the extjs panels
body: <p>I want to implement drag and drop buttons between the panels. Can this be done in a simple way? <a href="https://fiddle.sencha.com/#fiddle/rvg" rel="nofollow">I did example on Ext.ux.BoxReorderer</a>:</p>
  
  <pre><code>Ext.require(['Ext.ux.BoxReorderer']);
  
  Ext.application({
      name : 'Fiddle',
  
      launch : function() {
          Ext.create("Ext.panel.Panel", {
              renderTo: Ext.getBody(),
              title: "pnl1",
              plugins: Ext.create("Ext.ux.BoxReorderer"),
              layout: {
                  type: "hbox"
              },
              items: [{
                  xtype: "button",
                  text: "btn1"
              },{
                  xtype: "button",
                  text: "btn2"
              },{
                  xtype: "button",
                  text: "btn3"
              }]
          });
  
          Ext.create("Ext.panel.Panel", {
              renderTo: Ext.getBody(),
              title: "pnl2",
              plugins: Ext.create("Ext.ux.BoxReorderer"),
              layout: {
                  type: "hbox"
              },
              items: [{
                  xtype: "button",
                  text: "btn1"
              },{
                  xtype: "button",
                  text: "btn2"
              },{
                  xtype: "button",
                  text: "btn3"
              }]
          });
      }
  });
  </code></pre>
  
  <p>But do not know how to implement drag and drop between the panels.</p>
  
  <p>P.S. ExtJS version is 5.x.x</p>