@Test
  public void testNullPassword() throws Exception {
    assertThat(PasswordUtil.decrypt(null)).isNull();
  }
Tests PasswordUtil's decrypt method (which is now deprecated) and verifies that backwards
compatibility has not been broken with the removal of PasswordUtil's encryption methods.
Previously encrypted passwords may still be used and decrypted.
geode-core/src/test/java/org/apache/geode/internal/util/PasswordUtilJUnitTest.java