   @doc """
   Logs an error.
 
+  Returns the atom `:ok` or an `{:error, reason}` tuple.
+
   ## Examples
 
       Logger.error "oops"


  @doc """
  Logs a message.

  Developers should use the macros `Logger.debug/2`,
  `Logger.warn/2`, `Logger.info/2` or `Logger.error/2` instead

  @doc """
  Logs some info.

  Returns the atom `:ok` or an `{:error, reason}` tuple.

  ## Examples

      Logger.info "mission accomplished"
