title: Google classroom api: Keep getting 400 invalid argument
body: <p>I am testing the google classroom api using the google playground environment.  Everytime I make a post request to this endpoint: <a href="https://classroom.googleapis.com/v1/courses" rel="nofollow noreferrer">https://classroom.googleapis.com/v1/courses</a>, I keep getting this error:</p>
  
  <pre><code>{
    "error": {
      "status": "INVALID_ARGUMENT", 
      "message": "Request contains an invalid argument.", 
      "code": 400
    }
  }
  </code></pre>
  
  <p>This is my POST body that I am sending to the endpoint:</p>
  
  <pre><code>{
    "id": "1234T",
    "name": "Physics 101",
    "section": "Period 2",
    "room": "101",
    "ownerId": "me"
  }
  </code></pre>
  
  <p>I am passing all of the necessary items such as Bearer token, etc. and as far as I can tell I am also passing the necessary fields in the json body. What is causing this error and how can I fix it. </p>