ApiPlatform\Core\EventListener\AddFormatListener::populateMimeTypes PHP Method

    private function populateMimeTypes()
    {
        if (null !== $this->mimeTypes) {
            return;
        }
        $this->mimeTypes = [];
        foreach ($this->formats as $format => $mimeTypes) {
            foreach ($mimeTypes as $mimeType) {
                $this->mimeTypes[$mimeType] = $format;
            }
        }
    }