}

  fun assertBinaryMessage(payload: ByteString?) {
    assertThat(nextEvent()).isEqualTo(Message(payload))
  }

  fun assertPing(payload: ByteString) {
    assertThat(nextEvent()).isEqualTo(Ping(payload))
  }

  fun assertPong(payload: ByteString) {
    assertThat(nextEvent()).isEqualTo(Pong(payload))
  }

  fun assertClosing(
    code: Int,
    reason: String,
  ) {

    boolean suppressGetSupertype() default false;
  }

  private @Nullable Method method = null;

  /** Call this in a {@link TestSubtype} public method asserting subtype relationship. */
  final <T> T isSubtype(T sub) {
    Type returnType = method.getGenericReturnType();
    Type paramType = getOnlyParameterType();
    TestSubtype spec = method.getAnnotation(TestSubtype.class);

import junit.framework.Assert;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullMarked;

/**
 * Tests serialization and deserialization of an object, optionally asserting that the resulting
 * object is equal to the original.
 *
 * <p><b>GWT warning:</b> Under GWT, both methods simply returns their input, as proper GWT