code: function(obj) {
          var pruned = {};
          _.each(obj, function(value, key) {
              if (!_.isUndefined(value) && !_.isNull(value)) {
                  pruned[key] = value;
              }
          });
  
          return pruned;
      }
docs: Omits all undefined or null properties of given object.
  @param {Object} obj - object
  @returns {Object}