val client = clientTestRule.newClient()

    // Values should be non-null.
    val a = client.newBuilder().build()
    assertThat(a.dispatcher).isNotNull()
    assertThat(a.connectionPool).isNotNull()
    assertThat(a.sslSocketFactory).isNotNull()
    assertThat(a.x509TrustManager).isNotNull()

    // Multiple clients share the instances.
    val b = client.newBuilder().build()
    assertThat(b.dispatcher).isSameAs(a.dispatcher)