code: function relative2absolute(id, baseId) {
          if (id.indexOf('.') !== 0) {
              return id;
          }
  
          var segs = baseId.split('/').slice(0, -1).concat(id.split('/'));
          var res = [];
          for (var i = 0; i < segs.length; i++) {
              var seg = segs[i];
  
              switch (seg) {
                  case '.':
                      break;
                  case '..':
                      if (res.length && res[res.length - 1] !== '..') {
                          res.pop();
                      }
                      else { // allow above root
                          res.push(seg);
                      }
                      break;
                  default:
                      seg && res.push(seg);
              }
          }
  
          return res.join('/');
      }
docs: 相对id转换成绝对id
  
  @inner
  @param {string} id 要转换的相对id
  @param {string} baseId 当前所在环境id
  @return {string} 绝对id