varnish5 - how to view what currently is in cache?

[Admin Beckspaced]

hello again varnish users,

i have been looking in the varnish 5 documents.
found useful things like:

varnishadm
varnishtop
varnishhist
varnishstat

but how would i proceed if i want to know what actually is in the cache?

e.g. view a cached version of an URL: http://mydomain.com/somepage

or view cached versions based on custom hash_data i added via vcl

http://mydomain.com/somepage - hash_data lang=en
http://mydomain.com/somepage - hash_data lang=de
http://mydomain.com/somepage - hash_data lang=fr

is it possible to get a list of all URL's in cache?

and view a cached object based on the URL? perhaps custom hash_data?

e.g. varnishadm -view -url http://mydomain.com/somepage
e.g. varnishadm -view -url http://mydomain.com/somepage -hash_data lang=en
e.g. varnishadm -view -url http://mydomain.com/somepage -hash_data lang=de

any thoughts or hints would be great ;)

thanks & greetings
becki