code: function getFilter(name) {
      if (name in this._filters) {
        return this._filters[name];
      }
      else if (this._parent) {
        return this._parent.getFilter(name);
      }
  
      throw new Error("Missing filter " + name);
    }
docs: Retrieves a filter locally registered, or via the parent.
  
  @memberOf module:shared/get_filter
  @param {string} name - The name of the filter to retrieve.