code: function(cap, dispatchEvent) {
    this.mod = cap.module;
    this.dispatchEvent = dispatchEvent;
    util.handleEvents(this);
  
    // The Core object for managing channels.
    this.mod.once('core', function(Core) {
      this.core = new Core();
    }.bind(this));
    this.mod.emit(this.mod.controlChannel, {
      type: 'core request delegated to echo',
      request: 'core'
    });
  }
docs: A minimal provider implementing the core.echo interface for interaction with
  custom channels.  Primarily used for testing the robustness of the custom
  channel implementation.
  @Class Echo_unprivileged
  @constructor
  @param {module:Module} cap The module creating this provider.