Sometimes it's necessary to see what's inside a package which was not installed. Normally I use apt-file for this purpose. At most times this works fine, but in some cases I can't retrieve any information about the package contents using apt-file, meanwhile such a package have some files inside and seems not to be a meta package.
For example: Ubuntu 16.04 lts amd64, package name: linux-image-4.15.0-1010-oracle.
If I download it, using apt-get download and then extract, I can see
vmlinuz-4.15.0-1010-oracle file inside of it.
apt-file show linux-image-4.15.0-1010-oracle shows nothing.
apt-file update was made before any usage of apt-file.
So how should I use apt-file to see content information for this package? And why it shows me nothing?