// End of iteration behavior
        assertFalse(it.hasNext(), "No more elements expected");
        assertNull(it.next(), "next() returns null when exhausted in this implementation");
    }

    @Test
    @DisplayName("With filter: only accepted entries are returned and filter is invoked per entry")

        list += element
      }
      return list
    }

    private fun unescape(s: String): String =
      buildString {
        val buffer = Buffer().writeUtf8(s)
        while (!buffer.exhausted()) {
          val c = buffer.readUtf8CodePoint()
          if (c != '\\'.code) {
            append(c.toChar())
            continue
          }
          when (buffer.readUtf8CodePoint()) {

      assertTrue(
          "index " + i + " expected <" + expected + "., actual is exhausted",
          actualIterator.hasNext());

      Object actual = actualIterator.next();
      assertEquals("index " + i, expected, actual);
      i++;
    }
    if (actualIterator.hasNext()) {
      fail("index " + i + ", expected is exhausted, actual <" + actualIterator.next() + ">");
    }
  }

  /**

    // Write each byte into a new buffer, then clone it so that the segments are shared.
    // Shared segments cannot be compacted so we'll get a long chain of short segments.
    val result = Buffer()
    while (!buffer.exhausted()) {
      val box = Buffer()
      box.write(buffer, 1)
      result.write(box.copy(), 1)
    }
    return result
  }

  tailrec fun File.isDescendentOf(directory: File): Boolean {

    try {
      while (currentTask != self) {
        taskRunner.wait()
      }
    } finally {
      serialTaskQueue.remove(yieldCompleteTask)
    }

    // If we're yielding until we're exhausted and a task run, keep going until a task doesn't run.
    if (strategy == ResumePriority.AfterOtherTasks && otherTasksStarted) {
      return yieldUntil(strategy, condition)
    }
  }

 * bookkeeping easier for the caller: releasing the allocation as soon as the terminal stream has
 * been found. But only complete the stream once its data stream has been exhausted.
 */
interface Connection {
  /** Returns the route used by this connection. */
  fun route(): Route

  /**
   * Returns the socket that this connection is using. Returns an

 *
 * <p>The value you pass to the parameter {@code steps} should be greater than the length of your
 * iterator, so that this class can check that your iterator behaves correctly when it is exhausted.
 *
 * <p>For example, to test {@link java.util.Collections#unmodifiableList(java.util.List)
 * Collections.unmodifiableList}'s iterator:
 *
 * {@snippet :
 * List<String> expectedElements =

          maskCursor.seek(messageFrameBuffer.size - frameLength)
          toggleMask(maskCursor, maskKey!!)
          maskCursor.close()
        }
      }

      if (isFinalFrame) break // We are exhausted and have no continuations.

      readUntilNonControlFrame()
      if (opcode != OPCODE_CONTINUATION) {
        throw ProtocolException("Expected continuation opcode. Got: ${opcode.toHexString()}")
      }
    }

    }

    /**
     * Returns a value in [0..maxByteCount] with the number of bytes that can be read from [source]
     * in the current part. If this returns 0 the current part is exhausted; otherwise it has at
     * least one byte left to read.
     */
    private fun currentPartBytesRemaining(maxByteCount: Long): Long {
      val toIndex = minOf(source.buffer.size, maxByteCount) + 1L

            sink.writeUtf8("client says goodbye\n")
            sink.flush()

            assertThat(source.readUtf8Line()).isEqualTo("server says goodbye")

            assertThat(source.exhausted()).isTrue()
          }
        }
        socketHandler.awaitSuccess()
      }
  }

  @Test
  fun upgrade() {
    executeAndCheckUpgrade(upgradeRequest())
  }

  @Test