docs: private void releaseAllBlocks() throws IOException {
          synchronized (m_accessLock) {
              Set<Map.Entry<BlockId, Path>> entries = m_blockPathMap.entrySet();
              while (! entries.isEmpty()) {
                  Map.Entry<BlockId, Path> entry = entries.iterator().next();
                  Files.delete(entry.getValue());
                  m_blockPathMap.remove(entry.getKey());
                  entries = m_blockPathMap.entrySet();
              }
          }
      }