Need to provide a custom search engine id, although the tool tip says no authorisation required

What steps will reproduce the problem?
1.
2.
3.

Looking for metadata output for a simple query on 
http://developers.google.com/apis-explorer/#p/customsearch/v1/search.cse.list?q=
quercus&_h=1&

Instead I see this error:
412 Precondition Failed

- Show headers -

{
"error": {
"errors": [
{
"domain": "global",
"reason": "conditionNotMet",
"message": "Need to provide a Custom Search Engine ID. Missing cx or cref 
parameter.",
"locationType": "header",
"location": "If-Match"
}
],
"code": 412,
"message": "Need to provide a Custom Search Engine ID. Missing cx or cref 
parameter."
}
}

What is the expected output? What do you see instead?

Accessing with Firefox on Debian Linux, I guess it doesn't matter.

Original issue reported on code.google.com by paul.rou...@gmail.com on 6 Aug 2014 at 3:20

google-code-export / google-apis-explorer

Need to provide a custom search engine id, although the tool tip says no authorisation required #197