code: function normalizeTokens(relative, tokens) {
      var _index = 0;
  
      // Force as an array
      if (!_.isArray(tokens)) tokens = [tokens];
  
      return _.map(tokens, function(subtoken) {
          if (_.isNull(subtoken)) return null;
          if (_.isString(subtoken)) {
              subtoken = {
                  value: subtoken,
                  index: _index,
                  offset: subtoken.length
              };
          }
  
          if (_.isObject(subtoken)) {
              subtoken.index = subtoken.index || 0;
              _index = _index + subtoken.index + subtoken.offset;
  
              // Transform as an absolute token
              subtoken.index = relative.index + subtoken.index;
              subtoken.offset = subtoken.offset || subtoken.value.length;
          }
  
          return subtoken;
      });
  }
docs: Normalize and resolve a list of tokens relative to a token