}

    @Test
    @DisplayName("Should handle null in middle of multiple elements")
    void testJoinNullInMiddle() {
        String result = StringUtil.join("-", "start", null, null, "end");
        assertEquals("start-null-null-end", result);
    }

        a.append(csq);
        return this;
      }

      @Override
      public Appendable append(CharSequence csq, int start, int end) throws IOException {
        a.append(csq, start, end);
        return this;
      }

      @Override
      public Appendable append(char c) throws IOException {
        a.append(c);
        return this;
      }
    };

        a.append(csq);
        return this;
      }

      @Override
      public Appendable append(CharSequence csq, int start, int end) throws IOException {
        a.append(csq, start, end);
        return this;
      }

      @Override
      public Appendable append(char c) throws IOException {
        a.append(c);
        return this;
      }
    };

 * limitations under the License.
 */
package okhttp3.slack;

import java.util.List;
import okhttp3.HttpUrl;

/** See https://api.slack.com/methods/rtm.start. */
public final class RtmStartResponse {
  HttpUrl url;
  Object self;
  Object team;
  List<Object> users;
  List<Object> channels;
  List<Object> groups;
  List<Object> mpims;
  List<Object> ims;

    }

    @Override
    public int size() {
        return TRANSFORM_HEADER_SIZE;
    }

    @Override
    public int encode(final byte[] dst, int dstIndex) {
        final int start = dstIndex;

        // Protocol ID
        SMBUtil.writeInt4(TRANSFORM_PROTOCOL_ID, dst, dstIndex);
        dstIndex += 4;

        // Signature (16 bytes)

            Thread thread2 = new Thread(() -> transportPool.getSmbTransport(context, address, DEFAULT_PORT, true));

            thread1.start();
            thread2.start();
            thread1.join();
            thread2.join();

            // Then
            verify(transportPool, times(2)).getSmbTransport(any(), any(Address.class), anyInt(), anyBoolean());

 * @JvmField @Rule val serverRule = MockWebServerRule()
 * ```
 */
class MockWebServerRule : ExternalResource() {
  val server: MockWebServer = MockWebServer()

  override fun before() {
    try {
      server.start()
    } catch (e: IOException) {
      throw RuntimeException(e)
    }
  }

  override fun after() {
    server.close()
  }

  @Test
  fun passingTest() {
    assertThat("hello").isEqualTo("hello")
  }

  @Test
  fun testMockWebServer() {
    server.enqueue(MockResponse(body = "abc"))
    server.start()

    client.newCall(Request(url = server.url("/"))).execute().use {
      assertThat(it.body.string()).isEqualTo("abc")
    }
  }

  @Test
  fun testExternalSite() {

  public abstract boolean find();

  public abstract boolean find(int index);

  public abstract String replaceAll(String replacement);

  public abstract int end();

  public abstract int start();

        // Assert - message preserved, cause null
        assertEquals(message, ex.getMessage());
        assertNull(ex.getCause());

        // Assert - toString starts with class name and contains message when present
        if (message == null) {
            assertEquals(SMBProtocolDowngradeException.class.getName(), ex.toString());
        } else if (message.isEmpty()) {