   """
 
   @doc """
-  Invoked when the handler is added to the `GenEvent` process. `add_handler/3`,
+  Invoked when the handler is added to the `GenEvent` process. `add_handler/3`
   (and `add_mon_handler/3`) will block until it returns.
 
   `args` is the argument term (third argument) passed to `add_handler/3`.

  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


  end

  @doc """
  Sends an ack event notification to the event `manager`.

  In other words, this function only returns `:ok` as soon as the
  event manager starts processing this event, but it does not wait
