class Net::IMAP::Config

def initialize(parent = Config.global, **attrs)

If a block is given, the new config object is yielded to it.

If +parent+ is not given, the global config is used by default.

Creates a new config object and initialize its attribute with +attrs+. 
def initialize(parent = Config.global, **attrs)
  super(parent)
  update(**attrs)
  yield self if block_given?
end