code: public static int getIndexOfIgnoreCase (@Nullable final String sText,
                                            @Nonnegative final int nFromIndex,
                                            @Nullable final String sSearch,
                                            @Nonnull final Locale aSortLocale)
    {
      return sText != null &&
             sSearch != null &&
             (sText.length () - nFromIndex) >= sSearch.length ()
                                                                 ? sText.toLowerCase (aSortLocale)
                                                                        .indexOf (sSearch.toLowerCase (aSortLocale),
                                                                                  nFromIndex)
                                                                 : STRING_NOT_FOUND;
    }
docs: Get the first index of sSearch within sText ignoring case starting at index
  nFromIndex.
  
  @param sText
  The text to search in. May be <code>null</code>.
  @param nFromIndex
  The index to start searching in the source string
  @param sSearch
  The text to search for. May be <code>null</code>.
  @param aSortLocale
  The locale to be used for case unifying.
  @return The first index of sSearch within sText or {@value #STRING_NOT_FOUND}
  if sSearch was not found or if any parameter was <code>null</code>.
  @see String#indexOf(String)