code: public @NotNull ThrowableAssert isInstanceOf(@NotNull Class<? extends Throwable> type) {
      objectAssert.isInstanceOf(type);
      return this;
    }
docs: Verifies that the actual {@code Throwable} is an instance of the given type.
  
  @param type the type to check the actual {@code Throwable} against.
  @return this assertion object.
  @throws AssertionError       if the actual {@code Throwable} is {@code null}.
  @throws AssertionError       if the actual {@code Throwable} is not an instance of the given type.
  @throws NullPointerException if the given type is {@code null}.