Make root field transient in all classes

src/main/java/org/kohsuke/github/GHContent.java

@@ -15,15 +15,13 @@ import java.util.Base64;
  * @see GHRepository#getFileContent(String) GHRepository#getFileContent(String)
  */
 @SuppressWarnings({ "UnusedDeclaration" })
-public class GHContent implements Refreshable {
+public class GHContent extends GitHubInteractiveObject implements Refreshable {
     /*
      * In normal use of this class, repository field is set via wrap(), but in the code search API, there's a nested
      * 'repository' field that gets populated from JSON.
      */
     private GHRepository repository;
 
-    private GitHub root;
-
     private String type;
     private String encoding;
     private long size;