code: public void close() throws java.io.IOException{
          synchronized(this){
              if(_outHelper.isOutputStream_closed()){
                  if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                      Tr.debug(tc, "output stream close previously completed ...return ");
                  }
                  return;
              }
              else{
                  _outHelper.closeWork();
              }
          }
      }
docs: /* (non-Javadoc)
  @see java.io.OutputStream#close()