code: @Nonnull
    public String getStringWithFallback (@Nonnull final Charset aFallbackCharset)
    {
      final String sCharset = getCharSet ();
      final Charset aCharset = CharsetHelper.getCharsetFromNameOrDefault (sCharset, aFallbackCharset);
      return getString (aCharset);
    }
docs: Get the string with the charset defined in the content type.
  
  @param aFallbackCharset
  The fallback charset to be used if the content type does not include
  a charset. May not be <code>null</code>.
  @return The string representation of the item.