protected function validateRoots()
	{
		$roots = forward_static_call( [get_class( $this->model ), 'roots'] )->get();

		// If a scope is defined in the model we should check that the roots are
		// valid *for each* value in the scope columns.
		if ( $this->model->isScoped() )
			return $this->validateRootsByScope( $roots );

		return $this->isEachRootValid( $roots );
	}