docs: public final void clear() throws IOException {
          if ((bufferSize == 0) && (out != null))
              // clear() is illegal after any unbuffered output (JSP.5.5)
               throw new IllegalStateException("jsp.error.ise_on_clear");
          if (flushed)
              throw new IOException("jsp.error.attempt_to_clear_flushed_buffer");
          // defect 312981 begin
          //ensureOpen();
      	if (closed) {
      	    throw new IOException("Stream closed");
          }
          // defect 312981 end
          nextChar = 0;
      }