docs: @Nullable
      public File openFile(@NotNull final Transaction txn, @NotNull final String path, boolean create) {
          final ArrayByteIterable key = StringBinding.stringToEntry(path);
          final ByteIterable value = pathnames.get(txn, key);
          if (value != null) {
              return new File(path, value);
          }
          if (create) {
              return createFile(txn, path);
          }
          return null;
      }