Why is the Google Calendar API not accepting my bearer token? - oauth-2.0

Question

I am trying to learn OAuth 2.0 by walking through walking through making Google API call using Firefox 28.0 and REST Client v2.0.3.
I went to the Google Developer OAuth 2.0 Playground site.
I signed in using my Google credentials
Selected "Calendar API v3" .readonly
clicked the "Authorize APIs" button
Then I clicked "Exchage authorization code for tokens" and got the access token ab31.4.CDEfG_HI1JkKMNoPQR5S9tuvW_x2yzabcDEFGhiJklMnOpqRs-T6uvwXyza5BcdEFGHiJK3L
From the Calendar API, I use the URL https://www.googleapis.com/calendar/v3/users/me/calendarList wtih the GET HTTP action
In RESTClient I create a header with the name "Authorization" and set the value ab31.4.CDEfG_HI1JkKMNoPQR5S9tuvW_x2yzabcDEFGhiJklMnOpqRs-T6uvwXyza5BcdEFGHiJK3L to the from "Access token:" box from the OAuth 2.0 Playground.
With an empty Body I click SEND and I get an authorization error (the playground says my token is still valid for another 30 minutes)
The error's header is:
Status Code: 401 Unauthorized
Alternate-Protocol: 443:quic
Cache-Control: private, max-age=0
Content-Encoding: gzip
Content-Length: 162
Content-Type: application/json; charset=UTF-8
Date: Tue, 18 Mar 2014 19:17:35 GMT
Expires: Tue, 18 Mar 2014 19:17:35 GMT
Server: GSE
WWW-Authenticate: Bearer realm="https://www.google.com/accounts/AuthSubRequest"
X-Content-Type-Options: nosniff
X-Firefox-Spdy: 3.1
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
and the body is:
{
"error": {
"errors": [
{
"domain": "global",
"reason": "authError",
"message": "Invalid Credentials",
"locationType": "header",
"location": "Authorization"
}
],
"code": 401,
"message": "Invalid Credentials"
}
}

Answer 1

The header needs to be set to Authorization: Bearer ab31.4.CDEfG_HI1JkKMNoPQR5S9tuvW_x2yzabcDEFGhiJklMnOpqRs-T6uvwXyza5BcdEFGHiJK3L. You need the word "Bearer" preceding the token.