text: 'use strict'
  
  const leftJoin = (hm1, hm2) => {
      let temp = [];
      const rtn = [];
      const keys = Object.keys(hm1);;
      for(let i = 0; i < keys.length; i++) {
          temp.push(keys[i]);
          temp.push(hm1[keys[i]]);
          temp.push(hm2.hasOwnProperty(key[i] ? hm2[keys[i]] : null));
          rtn.push(temp);
          temp = [];
      }
      return rtn;
  }