In commit 5392be4d, there was a change
made when cleaning up the template for the API listing that caused 2
spaces to appear before every header item (except the first) and before
the first line of the body of the response. This meant that it often
looked like:

HTTP 200 OK
  Allow: GET, OPTIONS
  Content-Type: application/json
  Vary: Accept

  {
    "key": "value",
    "key2": "value2"
}

This change removes those leading spaces, so that it will now look like:

HTTP 200 OK
Allow: GET, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "key": "value",
    "key2": "value2"
}