code: @Nullable
    public static String getCharsetNameFromMimeType (@Nullable final IMimeType aMimeType)
    {
      return aMimeType == null ? null : aMimeType.getParameterValueWithName (CMimeType.PARAMETER_NAME_CHARSET);
    }
docs: Determine the charset name from the provided MIME type.
  
  @param aMimeType
  The MIME type to query. May be <code>null</code>.
  @return <code>null</code> if no MIME type was provided or if the MIME type
  does not contain a "charset" parameter