@Override public TupleEntryCollector openForWrite( FlowProcess<? extends Properties> flowProcess, OutputStream output ) throws IOException { if( output == null ) output = new TapFileOutputStream( getOutputIdentifier( flowProcess ), isUpdate() ); // append if we are in update mode return new TupleEntrySchemeCollector<Properties, OutputStream>( flowProcess, this, getScheme(), output, getIdentifier() ); }