private void readInHeader(@NotNull Path filePath) throws IOException {
    int magic = file.getInt(HEADER_MAGIC_OFFSET);
    if (magic != SAFELY_CLOSED_MAGIC) {
      IOException ioError = new IOException(
        "Records table for '" + filePath + "' haven't been closed correctly. Rebuild required."
      );
      try {
        file.close();
      }
      catch (IOException ioe) {
        ioError.addSuppressed(ioe);
      }
      throw ioError;
    }
    wasteSize = file.getInt(HEADER_WASTE_SIZE_OFFSET);
  }
private void readInHeader(@NotNull Path filePath)