code: function(blocks, in_tight_list) {
    var result = [];
    for (var i=0; i < blocks.length; i++) {
      if (blocks[i].t !== 'ReferenceDef') {
        result.push(this.renderBlock(blocks[i], in_tight_list));
      }
    }
    return result.join(this.blocksep);
  }
docs: Render a list of block elements, separated by this.blocksep.