code: @Nonnull
    @ReturnsMutableCopy
    public static char [] getAsCharArray (@Nonnull final Set <Character> aChars)
    {
      ValueEnforcer.notNull (aChars, "Chars");
  
      final char [] ret = new char [aChars.size ()];
      int nIndex = 0;
      for (final Character aChar : aChars)
        ret[nIndex++] = aChar.charValue ();
      return ret;
    }
docs: Convert the passed set to an array
  
  @param aChars
  Character set to use. May not be <code>null</code>.
  @return A new array with the same length as the source set.