问CytoscapeJS -显示节点邻域？

EN

function showNeighbourhood() {
   var eleID;
   var neighbourArray= new Array();

   var neighbours= cy.collection(); // collection

   cy.nodes().forEach(function( ele ) {
       if(ele.selected()) { // get the currently selected node.
          eleID= ele.id();
         }
      });

   // Find its connected neighbours.
   cy.edges().forEach(function( edg ) {
       if(edg.data('source') === eleID) {
          neighbourArray[neighbourArray.length]= edg.data('target');
         }
       else if(edg.data('target') === eleID) {
          neighbourArray[neighbourArray.length]= edg.data('source');
         }
      });

   // Add the array to the collection.
   neighbours.add(neighbourArray);

  // Show neighbourhood, using the collection.
   neighbours.show();
  }