StringBuilder uri = new StringBuilder(SEGMENT_REPOS);
uri.append('/').append(id);
uri.append(SEGMENT_GIT);
uri.append(SEGMENT_TREES);
uri.append('/').append(sha);
GitHubRequest request = createRequest();
request.setUri(uri);
System.out.println("uri: " + uri);
request.setType(Tree.class);
return (Tree) client.get(request).getBody();
}