title: Jenkins REST API - using tree to reference specific item in JSON array
body: <p>I am able to use the Jenkins API to get information about my build via the url </p>
  
  <pre><code>http://localhost:8080/job/myjob/149/api/json
  </code></pre>
  
  <p>I want to be able to query the changeSet node using the tree query string parameter. I can successfully query non-indexed nodes like "duration" via </p>
  
  <pre><code>http://localhost:8080/job/myjob/149/api/json?tree=duration
  </code></pre>
  
  <p>How do I query indexed nodes like changeSet?  I can't seem to find any doc anywhere.</p>
  
  <pre><code>{
      "actions": [
          {
              "causes": [
                  {
                      "shortDescription": "Started by an SCM change"
                  }
              ]
          },
          {},
          {},
          {}
      ],
      "artifacts": [],
      "building": false,
      "description": null,
      "duration": 80326,
      "estimatedDuration": 68013,
      "executor": null,
      "fullDisplayName": "my project #149",
      "id": "2013-06-14_14-31-06",
      "keepLog": false,
      "number": 149,
      "result": "SUCCESS",
      "timestamp": 1371234666000,
      "url": "http://localhost:8080/job/my project/149/",
      "builtOn": "",
      "changeSet": {
          "items": [
              {
                  "affectedPaths": [
                      "SearchViewController.m",
                      "Sample.strings"
                  ],
                  "author": {
                      "absoluteUrl": "http://localhost:8080/user/my user",
                      "fullName": "My User"
                  },
                  "commitId": "9032",
                  "timestamp": 1371234304048,
                  "date": "2013-06-14T18:25:04.048031Z",
                  "msg": "Author:my_author Description: changes Id: B-186199 Reviewer:reviewer_name",
                  "paths": [
                      {
                          "editType": "edit",
                          "file": "/branches/project_name/iOS/_MainLine/project_name/SearchViewController.m"
                      },
                                         ],
                  "revision": 9032,
                  "user": "user_name"
              }
          ],
          "kind": "svn",
          "revisions": [
              {
                  "module": "repo_url",
                  "revision": 8953
              },
              {
                  "module": "repo_url",
                  "revision": 9032
              }
          ]
      },
      "culprits": [
          {
              "absoluteUrl": "http://localhost:8080/user/username",
              "fullName": "username"
          }
      ]
  }
  </code></pre>