Box Salesforce toolkit -Get the Id of an exisiting SubFolder using parentfolderid, and folder name

Hi, My folder in BOX is structures as - ROOT Folder-- > Record Folder -->Sub Folder. The Record folder is the folder associated with a Custom Object on Salesforce. SubFolder is a folder called "Key" that resides under the Record Folder.  I am trying to upload a file into this  "Key" folder. Now if the folder does not exists, we want to first create and then upload the file. The issue is  - In the case the folder does exists, I get an error message but the id of the folder is not returned, which is retuned when creating a folder using toolkit.createfolder method. Is there a way to grab the id of existing subfolders using current toolkit methods.