How to set different verbosity to the default and custom sinks?

[vasabi-root]

I want to have different verbosity VLOG levels in the default stderr sink and my implementation of absl::LogSink. Docs says:

.WithVerbosity(int verbose_level)
Sets the verbosity field of the logged message as if it was logged by VLOG(verbose_level). Unlike VLOG(), this method does not affect whether statement is evaluated when the specified verbose_level has been disabled. The only effect is on LogSink implementations which make use of the absl::LogSink::verbosity() value. The value absl::LogEntry::kNoVerbosityLevel can be specified to mark the message not verbose.

I have several questions about this :

1. The absl::LogSink::verbosity() method is missing from absl::LogSink. May be absl::LogEntry::verbosity() was meant?
2. Anyway, if it is there somehow and I filter messages by absl::LogEntry::verbosity() in the absl::LogSink::Send impl, will it affect simple VLOG(verbose_level) message in my sink? If not, is there some way to do this?
3. I also want to have different absl::LogSeverity severity levels in the default sink and my implementation of absl::LogSink. How can I do it?