remove_by_filter

Description:

[ Version ( since = "0.6.3" ) ]
public bool remove_by_filter (PackageSackFilterFunc filter_cb)

Removes from the package sack any packages that return false from the filter function.

this	a valid PackageSack instance
filter_cb	a PackageSackFilterFunc, which returns `true` for the Package's to retain
user_data	user data to pass to `filter_cb`

true if a package was removed from the sack