docs: function get(obj, keyName) {
      if(obj == null || keyName == null) {
          return null;
      }
      if(keyName.indexOf('.') == -1) {
          return obj[keyName];
      }
      var keyNames = keyName.split('.');
      if(keyNames == null) {
          return null;
      }
      for(var i=0; i<keyNames.length; i++) {
          var res = obj[keyNames[i]];
          if(res == null) {
              return null;
          }
          obj = res;
      }
      return res;
  }