 
   @doc """
   Invoked to change the state of the handler when a different version of the
-  handler's module module is loaded (hot code swapping) and the state's term
+  handler's module is loaded (hot code swapping) and the state's term
   structure should be changed.
 
   `old_vsn` is the previous version of the module (defined by the `@vsn`

  As an example, let's have a GenEvent that accumulates messages until
  they are collected by an explicit call.

      # Define a Event Handler
      defmodule LoggerHandler do
        use GenEvent


    * `{:swapped, new_handler, pid}` - if the process pid has replaced the
      event handler by another

    * `term` - if the event handler is removed due to an error. Which term
      depends on the error

  Keep in mind that the `{:gen_event_EXIT, handler, reason}` message is not
