code: function eachEvt(evt, handler, thisArg, cb) {
      "use strict";
      if (evt instanceof Array) {
          evt.forEach(function (evt) {
              return cb(evt, handler, thisArg);
          });
          return true;
      }
      if (typeof evt === "object") {
          var _ret = (function () {
              var realThisArg = handler;
              if (realThisArg === undefined) {
                  realThisArg = null;
              }
              Object.entries(evt).forEach(function (_ref) {
                  var _ref2 = _slicedToArray(_ref, 2);
  
                  var evt = _ref2[0];
                  var handler = _ref2[1];
                  return cb(evt, handler, realThisArg);
              });
              return {
                  v: true
              };
          })();
  
          if (typeof _ret === "object") {
              return _ret.v;
          }
      }
      return false;
  }
docs: private methods 
  Utility method for iterating over multiple events in `on`, `off`, etc. If `evt` is an array,
  the callback is executed passing each item as `evt`, and passing `handler` and `thisArg` from
  the caller. If it is an object, however, the `evt` is the key and the `handler` is derived from
  the value in `evt[key]`. The `thisArg` is passed from the caller.
  
  @param {Array<string>|Object<function>} evt
  @param {function} handler
  @param {Object} thisArg
  @param {function} cb
  @returns {boolean} if `true`, `evt` was an array or object. If `false`, it wasn't.