code: function () {
              var flag = 0,
                  result = '',
                  char = '';
              var startPosition = this.position;
              while (this.position < this.source.length) {
                  char = this.source.substr(this.position, 1);
                  if (char === '(') {
                      flag++;
                  } else if (char === ')') {
                      flag--;
                  }
                  result += char;
                  if (flag === 0) {
                      break;
                  }
                  this.position++;
              }
              this.state = stateEnum.client;
              this.position++;
              if (flag !== 0) {
                  throw new SakerError('"(" not found the matched ")" ！', this.getStackString('"(" not found the matched ")" ！', this.getLineNum(startPosition)));
              }
              return result;
          }
docs: 读取@(...)内的代码。Read scripts in @()
  @returns {*}