@utilities.arguments_not_none<EOL><INDENT>def add_description(self, description):<DEDENT>
if self.get_descriptions_metadata().is_read_only():<EOL><INDENT>raise NoAccess()<EOL><DEDENT>if not isinstance(description, DisplayText):<EOL><INDENT>raise InvalidArgument('<STR_LIT>')<EOL><DEDENT>self.add_or_replace_value('<STR_LIT>', description)<EOL>
Adds a description.

        arg:    description (displayText): the new description
        raise:  InvalidArgument - ``description`` is invalid
        raise:  NoAccess - ``Metadata.isReadOnly()`` is ``true``
        raise:  NullArgument - ``description`` is ``null``
        *compliance: mandatory -- This method must be implemented.*