This method is only available on newer versions.
The first available version (v2_6_3) is shown here.
double_check_for(*)
public
@private This API on source might not be
stable, and for now we expect plugins to download all specs in `#specs`, so we
implement the method for compatibility purposes and leave it undocumented
(and don’t support) overriding it)
# File lib/bundler/plugin/api/source.rb, line 302
def double_check_for(*); end