question: public void addDatatransferProgressListener ( OnDatatransferProgressListener listener , OCUpload ocUpload ) { if ( ocUpload == null || listener == null ) return ; String targetKey = buildRemoteName ( ocUpload . getAccountName ( ) , ocUpload . getRemotePath ( ) ) ; mBoundListeners . put ( targetKey , listener ) ; }
target:  Adds a listener interested in the progress of the upload for a concrete file.