Custom Presentation layout

[Offbeatmammal]

I'm trying to set a widescreen, 13.333" x 7.5" size for my PowerPoint document.
fFom the samples (and what I can understand from the source) this should work

$objPHPPowerPoint = new PhpPresentation();
$objPHPPowerPoint->getLayout()->setDocumentLayout(DocumentLayout::LAYOUT_CUSTOM)
                            ->setCX(13.333,DocumentLayout::UNIT_INCH)
                            ->setCY(7.5,DocumentLayout::UNIT_INCH); 

but I get the following error

Fatal error: Uncaught TypeError: Cannot access offset of type string on string in 
C:\...d\vendor\phpoffice\phppresentation\src\PhpPresentation\DocumentLayout.php:138
Stack trace:
#0 C:\...\pptx.php(30): PhpOffice\PhpPresentation\DocumentLayout->setDocumentLayout('custom')
#1 {main}
  thrown in C:\...d\vendor\phpoffice\phppresentation\src\PhpPresentation\DocumentLayout.php on line 138

Using LAYOUT_SCREEN_16X9 and LAYOUT_OVERHEAD don't throw an error in generation, but PowerPoint repairs the file on opening

[Progi1984]

Fixed in #811 by @jiangzhangchan