text: 
  import Base from './base';
  
  /**
   * 视觉通道 pattern
   * @class Attr.pattern
   */
  class Pattern extends Base {
    constructor(cfg) {
      super(cfg);
      this.names = [ 'pattern' ];
      this.type = 'pattern';
      this.gradient = null;
    }
  }
  export default Pattern;
  