public function get_include_ids( $include = array() ) {
		// The following args are specific to group member queries, and
		// are not present in the query_vars of a normal BP_User_Query.
		// We loop through to make sure that defaults are set (though
		// values passed to the constructor will, as usual, override
		// these defaults).
		$this->query_vars = bp_parse_args( $this->query_vars, array(
			'group_id'     => 0,
			'group_role'   => array( 'member' ),
			'is_confirmed' => true,
			'invite_sent'  => null,
			'inviter_id'   => null,
			'type'         => 'last_joined',
		), 'bp_group_member_query_get_include_ids' );

		$group_member_ids = $this->get_group_member_ids();

		// If the group member query returned no users, bail with an
		// array that will guarantee no matches for BP_User_Query.
		if ( empty( $group_member_ids ) ) {
			return array( 0 );
		}

		if ( ! empty( $include ) ) {
			$group_member_ids = array_intersect( $include, $group_member_ids );
		}

		return $group_member_ids;
	}