ExecutionError expected = assertThrows(ExecutionError.class, () -> cache.get(new Object()));
    assertThat(expected).hasCauseThat().isSameInstanceAs(e);
    stats = cache.stats();
    assertEquals(1, stats.missCount());
    assertEquals(0, stats.loadSuccessCount());
    assertEquals(1, stats.loadExceptionCount());
    assertEquals(0, stats.hitCount());

    Iterator<String> iterator = asList("one", "two").iterator();
    IllegalArgumentException expected =
        assertThrows(IllegalArgumentException.class, () -> getOnlyElement(iterator));
    assertThat(expected).hasMessageThat().isEqualTo("expected one element but was: <one, two>");
  }

  public void testGetOnlyElement_noDefault_fiveElements() {

      sink.writeByte(0)
      sink.flush()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("stream finished")
    }
    assertFailsWith<IOException> {
      stream.source.read(Buffer(), 1)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("stream was reset: CANCEL")
    }

    // Verify the peer received what was expected.
    val synStream = peer.takeFrame()

    Iterator<String> iterator = asList("one", "two").iterator();
    IllegalArgumentException expected =
        assertThrows(IllegalArgumentException.class, () -> getOnlyElement(iterator));
    assertThat(expected).hasMessageThat().isEqualTo("expected one element but was: <one, two>");
  }

  public void testGetOnlyElement_noDefault_fiveElements() {

      client.newCall(
        Request
          .Builder()
          .url(server.url("/"))
          .build(),
      )
    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->
      assertThat(expected.message).isIn("timeout", "Read timed out")
    }
    assertThat(listener.recordedEventTypes()).containsExactly(
      "CallStart",
      "ProxySelectStart",
      "ProxySelectEnd",

      key = "has_space "
      cache.edit(key)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("keys must match regex [a-z0-9_-]{1,120}: \"$key\"")
    }
    assertFailsWith<IllegalArgumentException> {
      key = "has_CR\r"
      cache.edit(key)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("keys must match regex [a-z0-9_-]{1,120}: \"$key\"")
    }

    val call1 = client.newCall(Request(server.url("/")))
    assertFailsWith<IOException> {
      call1.execute()
    }.also { expected ->
      when (expected) {
        is SocketTimeoutException, is SSLException -> {}
        else -> throw expected
      }
    }

    // The second call times out because it uses the same bad connection.
    val call2 = client.newCall(Request(server.url("/")))

                    } catch (ExecutionException expected) {
                    }
                    try {
                      peeker.getDone(nonInput);
                      fail("Peeker should not be able to peek into non-input ClosingFuture.");
                    } catch (IllegalArgumentException expected) {
                    }
                    capturedPeeker.set(peeker);

    assertTrue(
        from.getType() + " is expected to be assignable to " + to.getType(),
        to.isSupertypeOf(from));
    assertTrue(
        to.getType() + " is expected to be a supertype of " + from.getType(),
        to.isSupertypeOf(from));
    assertTrue(
        from.getType() + " is expected to be a subtype of " + to.getType(), from.isSubtypeOf(to));
  }

  fun parseTrimsAsciiWhitespace() {
    val expected = parse("http://host/")
    // Leading.
    assertThat(parse("http://host/\u000c\n\t \r")).isEqualTo(expected)
    // Trailing.
    assertThat(parse("\r\n\u000c \thttp://host/")).isEqualTo(expected)
    // Both.
    assertThat(parse(" http://host/ ")).isEqualTo(expected)
    // Both.
    assertThat(parse("    http://host/    ")).isEqualTo(expected)