def find_members(search_string, location=None):
    """Return all members object corresponding to users which
        theirs fullname contains ``search_string``. Search is done at
        the given ``location`` if provided.

        :raises: :py:exc:`~silva.core.services.interfaces.MemberLookupError`
        :return: a list of :py:class:`~silva.core.interfaces.auth.IMember`
                 objects.
        """
