@fluent<EOL><INDENT>def expand(self, *relationships):<DEDENT>
for relationship in relationships:<EOL><INDENT>if relationship == '<STR_LIT>':<EOL><INDENT>relationship = '<STR_LIT>'.format(self.protocol.get_service_keyword('<STR_LIT>'))<EOL><DEDENT>self._expands.add(relationship)<EOL><DEDENT>return self<EOL>
Adds the relationships (e.g. "event" or "attachments")
        that should be expanded with the $expand parameter
        Important: The ApiComponent using this should know how to handle this relationships.
            eg: Message knows how to handle attachments, and event (if it's an EventMessage).
        Important: When using expand on multi-value relationships a max of 20 items will be returned.
        :param str relationships: the relationships tuple to expand.
        :rtype: Query