code: function jsonInData(data, keypath, delimiter = '.') {
      let r,
          tmp = data;
      keypath = keypath || [];
      typeof keypath == 'string' && (keypath = keypath.split(delimiter));
  
      if (!(data && keypath.length)) return r;
      keypath.map(val => {
          r = 0;
          if (val && tmp && val in tmp) {
              tmp = tmp[val];
              r = 1;
          }
      });
  
      return !!r;
  }
docs: 判断一个属性路径是否存在于 object
  @param {Object}      data        要判断的是否存在属性值的JSON
  @param {string}      keypath     属性路径
  @param {string}      delimiter   属性路径的分隔符，默认: "."
  @return {Boolean}
  @method jsonInData
  @example
  <pre>
  console.log( jsonInData( { 'l1': { 'l2': 1 } }, 'l1.l2' ) ); //return true
  console.log( jsonInData( { 'l1': { 'l3': 1 } }, 'l1.l2' ) ) ; //return false
  </pre>