Method is

packages/effect/src/unstable/socket/Socket.ts:372–374

* Returns `true` when the value is a `SocketError`. * * @since 4.0.0

(u: unknown)

   * @since 4.0.0
   */
  static is(u: unknown): u is SocketError {
    return isSocketError(u)
  }

  override readonly message = this.reason.message
}