code: function(eventType, listener) {
      var i, len, foundIndex, events, perEventHandlers, client = this, meta = _clientMeta[client.id], handlers = meta && meta.handlers;
      if (!handlers) {
        return client;
      }
      if (arguments.length === 0) {
        events = _keys(handlers);
      } else if (typeof eventType === "string" && eventType) {
        events = eventType.split(/\s+/);
      } else if (typeof eventType === "object" && eventType && !("length" in eventType) && typeof listener === "undefined") {
        _keys(eventType).forEach(function(key) {
          var listener = eventType[key];
          if (typeof listener === "function") {
            client.off(key, listener);
          }
        });
      }
      if (events && events.length) {
        for (i = 0, len = events.length; i < len; i++) {
          eventType = events[i].toLowerCase().replace(/^on/, "");
          perEventHandlers = handlers[eventType];
          if (perEventHandlers && perEventHandlers.length) {
            if (listener) {
              foundIndex = perEventHandlers.indexOf(listener);
              while (foundIndex !== -1) {
                perEventHandlers.splice(foundIndex, 1);
                foundIndex = perEventHandlers.indexOf(listener, foundIndex);
              }
            } else {
              perEventHandlers.length = 0;
            }
          }
        }
      }
      return client;
    }
docs: The underlying implementation of `ZeroClipboard.Client.prototype.off`.
  @private