code: public static boolean containsIgnoreCase (@Nullable final String sText,
                                              final char cSearch,
                                              @Nonnull final Locale aSortLocale)
    {
      return getIndexOfIgnoreCase (sText, cSearch, aSortLocale) != STRING_NOT_FOUND;
    }
docs: Check if cSearch is contained within sText ignoring case.
  
  @param sText
  The text to search in. May be <code>null</code>.
  @param cSearch
  The char to search for. May be <code>null</code>.
  @param aSortLocale
  The locale to be used for case unifying.
  @return <code>true</code> if sSearch is contained in sText,
  <code>false</code> otherwise.
  @see String#indexOf(int)