def initialize(address, username, options)
require 'net/ssh'
key_manager = Net::SSH::Authentication::KeyManager.new(nil, options)
unless options[:key_data] || options[:keys] || options[:password] || key_manager.agent
raise ArgumentError.new(':key_data, :keys, :password or a loaded ssh-agent is required to initialize SSH')
end
if options[:key_data] || options[:keys]
options[:keys_only] = true
options[:keys] = [] unless options[:keys]
options[:key_data] = [] unless options[:key_data]
end
@address = address
@username = username
@options = { :paranoid => false }.merge(options)
end