ctor() {
    const gl = cc._renderContext;

    // initialize properties that may be required in init
    this.objects = [];
    this._filteredObjects = [];
    this.verticesBuffer = gl.createBuffer();
    this.indicesBuffer = gl.createBuffer();
  }
*************************************************************************
 Batch
 var Batch = cc.Class
 Batch.create()
 // this batch is intended for more flexible or non-standard batching
 // (see cc.SpriteBatchNode for basic sprite batching, it is probably faster for that)
**************************************************************************