defmodule KV.Registry do
  use GenServer

  def start_link(opts) do
    # 1. Pass the name to GenServer's init
    server = Keyword.fetch!(opts, :name)
    GenServer.start_link(__MODULE__, server, opts)
  end
(...)

  @doc """
  Starts the registry with the given options.

  `:name` is always required.
  """