text: /** ********** *
   *
   * Prototype of canvas instance
   * - In develop mode, fps will throw warnings in low performance.
   *
   * ********** **/
  
  const PROTOS = {
      $dom: null,
      $paintContext: null,
      $nextTickTime: 0,
      $lastPaintTime: 0, // 只有当maxFps位于1～59时才不为0
      $pausing: false,
      $freezing: false,
  
      name: '',
      fps: 0,
      lastFps: 0,
      fpsCalculateTime: 0,
      fpsHandler: null,
      width: 0,
      height: 0,
      events: {
          click: null,
      },
      children: [],
      eHoldingFlag: false,
      eLastMouseHover: null,
  
      maxFps: -1,
  };
  
  if (process.env.NODE_ENV !== 'production') {
      PROTOS.$flags = {
          // dragging: false
      }
  }
  
  module.exports = PROTOS;
  