code: function readCall(walker, defaultArgs) {
      walker.goUntil();
      var result = readAccessor(walker);
  
      var args;
      if (walker.goUntil(40)) { // (
          args = [];
  
          while (!walker.goUntil(41)) { // )
              args.push(readTertiaryExpr(walker));
              walker.goUntil(44); // ,
          }
      }
      else if (defaultArgs) {
          args = defaultArgs;
      }
  
      if (args) {
          result = {
              type: ExprType.CALL,
              name: result,
              args: args
          };
      }
  
      return result;
  }
docs: 读取调用
  
  @param {Walker} walker 源码读取对象
  @param {Array=} defaultArgs 默认参数
  @return {Object}