def each
      current = first()
      return if current.nil?
      yield current
      current_delegate = current.ffi_delegate
      while current_delegate = current_delegate.next
        break if current_delegate.null?
        yield CZTop::Config.from_ffi_delegate(current_delegate)
      end
    end
def each
      current = first()
      return if current.nil?
      yield current
      current_delegate = current.ffi_delegate
      while current_delegate = current_delegate.next
        break if current_delegate.null?
        yield CZTop::Config.from_ffi_delegate(current_delegate)
      end
    end
Yields all direct children/younger siblings. Starts with {#first}, if
 set.
 @yieldparam config [Config]