docs: function parse(code, modules, options) {
          if (code === '') {
              // old version of esprima doesn't play nice with the empty string
              // and loc/range info so until we can upgrade hack in a single space
              code = ' ';
          }
          modules = modules ? loadedMacros.concat(modules) : modules;
          return parser.parse(expand(code, modules, options));
      }