title: C# JToken.SelectTokens Method - what JPath expression?
body: <p>I have json text like this:</p>
  
  <pre><code>{
  "course_editions": {
  "2014/SL": [
    {
      "grades": {
        "course_units_grades": {
          "159715": {
            "1": {
              "value_symbol": "4",
              "exam_session_number": 1,
              "exam_id": 198172,
              "value_description": {
                "en": "good",
              }
            }
          }
        },
        "course_grades": {}
      }
    },
    {
      "grades": {
        "course_units_grades": {
          "159796": {
            "1": {
              "value_symbol": "5",
              "exam_session_number": 1,
              "exam_id": 198259,
              "value_description": {
                "en": "very good",
              }
            }
          }
        },
        "course_grades": {}
      }
    },
  </code></pre>
  
  <p>I would like to use JToken.SelectTokens Method from Namespace: Newtonsoft.Json.Linq</p>
  
  <p>I've tried like this:</p>
  
  <pre><code>string json_response = GetResponse(sign(url_courses));
  var courses_tokens = JObject.Parse(json_response).SelectTokens("['course_editions'].['2014/SL'].[*].['grades'].*")
  </code></pre>
  
  <p>It doesn't work. I would like to get only these numbers after <code>course_unit_grades</code> and before <code>"1"</code>. So in this example only: <code>"159715"</code> and <code>"159796"</code> to be able to use all of them, one by one in </p>
  
  <pre><code>foreach(var lp in courses_tokens) {
  }
  </code></pre>