# File lib/net/ssh/authentication/methods/publickey.rb, line 16
16:           def authenticate(next_service, username, password=nil)
17:             return false unless key_manager
18: 
19:             key_manager.each_identity do |identity|
20:               return true if authenticate_with(identity, next_service, username)
21:             end
22: 
23:             return false
24:           end