code: function(keys, callback, action) {
      keys = keys instanceof Array ? keys : [keys];
      _bindMultiple(keys, callback, action);
      return this;
    }
docs: binds an event to mousetrap
  
  can be a single key, a combination of keys separated with +,
  an array of keys, or a sequence of keys separated by spaces
  
  be sure to list the modifier keys first to make sure that the
  correct key ends up getting bound (the last key in the pattern)
  
  @param {string|Array} keys
  @param {Function} callback
  @param {string=} action - 'keypress', 'keydown', or 'keyup'
  @returns void