Requiem.ConnectionSupervisor.lookup_connection

You're seeing just the function lookup_connection, go back to Requiem.ConnectionSupervisor module for more information.
Link to this function

lookup_connection(handler, dcid, address, arg4)

Specs

lookup_connection(module(), binary(), Requiem.Address.t(), boolean()) ::
  {:ok, pid()} | {:error, :not_found}