code: function(o) {
      var self = this;
  
      // Throw an error if no source is provided.
      if (!o.src || o.src.length === 0) {
        console.error('An array of source files must be passed with any new Howl.');
        return;
      }
  
      self.init(o);
    }
docs: Group Methods * ************************************************************************ 
  Create an audio group controller.
  @param {Object} o Passed in properties for this group.