return null;
        }

        return newDictionaryFile(encodePath(path), path, timestamp);
    }

    /**
     * Encodes a file path using Base64 URL-safe encoding.
     *
     * @param path the file path to encode
     * @return the Base64 encoded path
     */
    protected String encodePath(final String path) {

            // Verify path encoding (UTF-16LE)
            byte[] pathBytes = path.getBytes(StandardCharsets.UTF_16LE);
            byte[] encodedPath = new byte[pathBytes.length];
            bb.get(encodedPath);
            assertArrayEquals(pathBytes, encodedPath);

            // Verify null terminator
            assertEquals(0, bb.getShort());
        }

        @Test