private Predicate<Class<?>> classFilter =
      (Class<?> cls) -> visibility.isVisible(cls.getModifiers());

  /**
   * Restricts the sanity tests for public API only. By default, package-private API are also
   * covered.
   */
  protected final void publicApiOnly() {
    visibility = Visibility.PUBLIC;
  }

  /**

import java.util.stream.Stream;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * An expanded {@code Iterable} API, providing functionality similar to Java 8's powerful <a href=
 * "https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html#package.description"
 * >streams library</a> in a slightly different way.
 *
 * <p>The following types of methods are provided:
 *

  private Predicate<Class<?>> classFilter =
      (Class<?> cls) -> visibility.isVisible(cls.getModifiers());

  /**
   * Restricts the sanity tests for public API only. By default, package-private API are also
   * covered.
   */
  protected final void publicApiOnly() {
    visibility = Visibility.PUBLIC;
  }

  /**