   Will have a final value for `Repo` of:
 
       [log_level: :info, pool_size: 10]
+
+  This final value can be retrieved at run or compile time:
+
+      Application.get_env(:ecto, Repo)
 
   """
   defmacro config(app, key, opts) do


      [log_level: :info, mode: :truncate, threshold: 1024]

  """
  defmacro config(app, opts) do
    quote do

  Furthermore, this module provides functions like `read!/1`,
  `merge/2` and friends which help manipulate configurations
  in general.

  Configuration set using `Mix.Config` will set the application env, so
  that `Application.get_env/3` and other `Application` functions can be used
  at run or compile time to retrieve or change the configuration.

  For example, the `:key1` value from application `:plug` (see above) can be
  retrieved with:

      "value1" = Application.fetch!(:plug, :key1)

  """

  defmodule LoadError do
