question: private List < String > fetchFileCosIdList ( ) throws SOSFailure { final String methodName = "fetchFileCosIdList(): " ; log . trace ( methodName + "Entry" ) ; final String FILE_COS_URI = "/file/vpools" ; List < String > fileCosIdList = new ArrayList < String > ( ) ; try { CoSList cosElemList = _client . queryObject ( FILE_COS_URI , CoSList . class ) ; if ( cosElemList != null && cosElemList . getCosElements ( ) != null ) { for ( CoSElement elem : cosElemList . getCosElements ( ) ) { if ( elem != null ) { fileCosIdList . add ( elem . getId ( ) ) ; } } } log . trace ( methodName + "File CoS Ids: " + fileCosIdList ) ; if ( cosElemList != null && fileCosIdList != null ) { log . trace ( methodName + "Exit returning cos list of size[" + fileCosIdList . size ( ) + "]" ) ; return fileCosIdList ; } log . trace ( methodName + "Exit returning cos list of size[0]" ) ; return new ArrayList < String > ( ) ; } catch ( NoSuchAlgorithmException e ) { log . error ( methodName + "NoSuchAlgorithmException occured" , e ) ; throw new SOSFailure ( e ) ; } catch ( UniformInterfaceException e ) { log . error ( methodName + "UniformInterfaceException occured" , e ) ; throw new SOSFailure ( e ) ; } }
target:  Returns list of file Cos Ids