code: public static String substringLastFrontIgnoreCase(String str, String... delimiters) {
          assertStringNotNull(str);
          return doSubstringFirstRear(true, false, true, str, delimiters);
      }
docs: Extract front sub-string from last-found delimiter ignoring case.
  <pre>
  substringLastFront("foo.bar/baz.qux", "A", "U")
  returns "foo.bar/baz.q"
  </pre>
  @param str The target string. (NotNull)
  @param delimiters The array of delimiters. (NotNull)
  @return The part of string. (NotNull: if delimiter not found, returns argument-plain string)