### Question:
HiveUtils { @Nonnull public static String quoteIdentifier(@Nonnull final String identifier) { return "`" + identifier.replaceAll("`", "``") + "`"; } private  HiveUtils(); @Nonnull static String quoteIdentifier(@Nonnull final String identifier); static String quoteDataType(@Nonnull final String dataType); @Nonnull static String quoteIdentifier(@Nullable final String first, @Nonnull final String second); @Nonnull static String quoteString(@Nonnull final String string);  }### Answer:
@Test public void quoteIdentifier() { Assert.assertEquals("`test`", HiveUtils.quoteIdentifier("test")); Assert.assertEquals("`test``s`", HiveUtils.quoteIdentifier("test`s")); Assert.assertEquals("`test`", HiveUtils.quoteIdentifier(null, "test")); Assert.assertEquals("`default`.`test`", HiveUtils.quoteIdentifier("default", "test")); }