iOS Google Drive SDK - Query string for folders doesn't appear to be working

iOS Google Drive SDK - Query string for folders doesn't appear to be working

Per GTLQueryDrive.h method documentation:
// Method: drive.files.list
// Lists the user's files.
// Optional:
// q: Query string for searching files.
// Fetches a GTLDriveFileList.
+ (id)queryForFilesList;
Also here: https://developers.google.com/drive/search-parameters Second
item under the Examples heading:
Search for folders using the folder-specific MIME type
mimeType = 'application/vnd.google-apps.folder'
When I perform a queryForFilesList and set q, I get a non-error result but
the contents of the GTLFileList only has two properties set, kind and
etag. There is nothing else returned in the results. See below:
GTLQueryDrive *query = [GTLQueryDrive queryForFilesList];
query.q = @"mimeType='application/vnd.google-apps.folder'";
[self.fileChecker executeQuery:query completionHandler:^(GTLServiceTicket
*ticket, id object, NSError *error) {
if (!error) {
//I see this in the console...
//No Errors in Folder Query:
//GTLDriveFileList 0x108f3430: {kind:"drive#fileList"
//etag:""Q5ElJByAJoL0etObruYVPRipH1k/vyGp6PvFo4RvsFtPoIWeCReyIC8""}
NSLog(@"No Errors in Folder Query: %@",object);
GTLDriveFileList *list = (GTLDriveFileList *)object;
//So, none of this for() loop happens
for (GTLDriveFile *file in list.items) {
NSLog(@"Folder: \n \n %@ \n \n",file);
}
} else {
NSLog(@"Folder Query Error: %@",error);
}
}];
Anything I'm doing wrong? The iOS Google Drive app can definitely find a
list of Folders. What am I doing wrong?