def get_primary_or_secondary(self, component, return_ind=False):
        """
        return whether a given component is the 'primary' or 'secondary'
        component in its parent orbit
        """
        parent = self.get_parent_of(component)
        if parent is None:
            # then this is a single component, not in a binary
            return 'primary'

        children_of_parent = self.get_children_of(parent)

        ind = children_of_parent.index(component)

        if ind > 1:
            return None

        if return_ind:
            return ind + 1

        return ['primary', 'secondary'][ind]
return whether a given component is the 'primary' or 'secondary'
        component in its parent orbit