  def initialize(remote_host, remote_port, local_host = nil, local_port = nil)
    if Thread.current[:private_address_check] && PrivateAddressCheck.resolves_to_private_address?(remote_host)
      raise PrivateAddressCheck::PrivateConnectionAttemptedError
    end

    initialize_without_private_address_check(remote_host, remote_port, local_host, local_port)
  end
The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.