docs: void releaseBlock(BlockId blockId) throws IOException {
          synchronized (m_accessLock) {
              if (! m_blockPathMap.containsKey(blockId)) {
                  throw new IllegalArgumentException("Request to release block that is not stored: " + blockId);
              }
  
              Path blockPath = m_blockPathMap.get(blockId);
              Files.delete(blockPath);
              m_blockPathMap.remove(blockId);
          }
      }