How to move pagefile to a different page via API?

[hellomoto]

This did not work...

                $np = new Page();
                $np->parent = $page;
                $np->template = 'upload';
                $np->title = 'tmp';
                $np->save();
                $np->of(false);
                $np->uploaded->add($f);
                $np->title = $f->basename;//$t->description;
                $np->name = $sanitizer->name($np->title);
                $np->save();
                $this->message('Uploaded to new page: '.$np->title);

                wire('pagefiles')->delete($f);

Error: Call to a member function add() on null

Edited 4 hours ago by hellomoto

[hellomoto]

                $np = new Page();
                $np->of(false);
                $np->parent = $page->id;
                $np->template = $make;
                $np->title = 'tmp';
                $np->addStatus('unpublished');
                $np->save();
                $np->uploaded->add($f);
                $np->title = $f->basename;
                $np->save();
                $this->message('Uploaded to new page '.$np->id.': '.$np->title);

                $page->upload->delete($f);
                $page->save(['noHooks' => true]);

works