Function get_parent_children_via 

pub fn get_parent_children_via(
    parent: &SpaceHierarchyParentSummary,
    suggested_only: bool,
) -> impl DoubleEndedIterator<Item = (OwnedRoomId, impl Iterator<Item = OwnedServerName>)> + '_

Returns the children of a SpaceHierarchyParentSummary, making use of the children_state field