this.mutex = mutex;
  }

  @Override
  protected Set<E> delegate() {
    return delegate;
  }

  @Override
  public String toString() {
    assertTrue(Thread.holdsLock(mutex));
    return super.toString();
  }

  @Override
  public boolean equals(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.equals(o);
  }

  @Override
  public int hashCode() {

	n, err = r.reader.Read(p)
	atomic.AddInt64(&r.bytesRead, int64(n))
	return n, err
}

func (r *countUpReader) BytesRead() int64 {
	if r == nil {
		return 0
	}
	return atomic.LoadInt64(&r.bytesRead)
}

func newCountUpReader(reader io.Reader) *countUpReader {
	return &countUpReader{
		reader: reader,
	}
}

type progressReader struct {
	rc              io.ReadCloser

            return false;
          }
        }
        return true;
      } catch (ClassCastException e) {
        return false;
      } catch (NoSuchElementException e) {
        return false; // concurrent change to other set
      }
    }
    return containsAll(that);
  }

  @Override
  public E first() {
    if (isEmpty()) {

    public int getFetchSize() {
        return getSqlClause().getFetchSize();
    }

    @Override
    public int getFetchPageNumber() {
        return getSqlClause().getFetchPageNumber();
    }

    @Override
    public int getPageStartIndex() {
        return getSqlClause().getPageStartIndex();
    }

    @Override
    public int getPageEndIndex() {
        return getSqlClause().getPageEndIndex();
    }

    final int characteristics() {
      return spliterator.characteristics();
    }

    final long estimateSize() {
      return spliterator.estimateSize();
    }

    final @Nullable Comparator<? super E> getComparator() {
      return spliterator.getComparator();
    }

    final long getExactSizeIfKnown() {
      return spliterator.getExactSizeIfKnown();
    }

    final int characteristics() {
      return spliterator.characteristics();
    }

    final long estimateSize() {
      return spliterator.estimateSize();
    }

    final @Nullable Comparator<? super E> getComparator() {
      return spliterator.getComparator();
    }

    final long getExactSizeIfKnown() {
      return spliterator.getExactSizeIfKnown();
    }

    //                                                                             =======
    @Override
    public ThumbnailQueueDbm asDBMeta() {
        return ThumbnailQueueDbm.getInstance();
    }

    @Override
    public String asTableDbName() {
        return "thumbnail_queue";
    }

    // ===================================================================================

         */

        return dstIndex - start;
    }

    /**
     * @param il
     * @return
     */
    private static int mapInformationLevel(final int il) {
        switch (il) {
        case FileSystemInformation.SMB_INFO_ALLOCATION:
            return 0x1;
        case FileSystemInformation.FS_SIZE_INFO:
            return 0x103;
        }

                return fessConfig.get(propertyKey);
            }

            @Override
            public BigDecimal getAsDecimal(String propertyKey) {
                return DfTypeUtil.toBigDecimal(get(propertyKey));
            }

            @Override
            public Integer getAsInteger(String propertyKey) {
                return DfTypeUtil.toInteger(get(propertyKey));
            }

    /**
     * Gets the default current page number.
     * @return The default current page number.
     */
    protected int getDefaultCurrentPageNumber() {
        return DEFAULT_CURRENT_PAGE_NUMBER;
    }

    /**
     * Gets the total number of records.
     * @return The total record count.
     */
    public int getAllRecordCount() {
        return allRecordCount;
    }

    /**