@Test
    @DisplayName("Should handle null input gracefully")
    void testNullInputHandling() {
        // When/Then
        assertThrows(NullPointerException.class, () -> {
            MessageDigest md4 = Crypto.getMD4();
            md4.digest(null);
        });

        assertThrows(NullPointerException.class, () -> {
            MessageDigest md5 = Crypto.getMD5();
            md5.digest(null);
        });
    }

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.Mockito.doNothing;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import org.junit.jupiter.api.BeforeEach;

    assertThrows(NoSuchElementException.class, () -> iterator.next());
    assertThrows(IllegalStateException.class, () -> iterable.iterator());
  }

  public void testFrom_one() {
    Iterable<String> iterable = MinimalIterable.from(singleton("a"));
    Iterator<String> iterator = iterable.iterator();
    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());

  public void testParse_weakValuesCannotHaveValue() {
    assertThrows(IllegalArgumentException.class, () -> parse("weakValues=true"));
  }

  public void testParse_repeatedValueStrength() {
    assertThrows(IllegalArgumentException.class, () -> parse("softValues, softValues"));

    assertThrows(IllegalArgumentException.class, () -> parse("softValues, weakValues"));

     * ability to throw the correct exception in the future.
     */
    assertThrows(NoSuchElementException.class, iter::peek);
    assertThrows(NoSuchElementException.class, iter::peek);
    assertThrows(NoSuchElementException.class, iter::next);
    assertThrows(NoSuchElementException.class, iter::peek);
  }


  @J2ktIncompatible // weak references, details of GC

        .of(-1.375);
    assertThat(DoubleMath.mean(ImmutableList.of(1.1))).isWithin(1.0e-10).of(1.1);
    assertThrows(IllegalArgumentException.class, () -> DoubleMath.mean(ImmutableList.<Double>of()));
    assertThrows(
        IllegalArgumentException.class, () -> DoubleMath.mean(ImmutableList.of(Double.NaN)));
    assertThrows(
        IllegalArgumentException.class,
        () -> DoubleMath.mean(ImmutableList.of(Double.POSITIVE_INFINITY)));

    Set<Integer> nodes = network.nodes();
    assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(network.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test
  public void edges_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<String> edges = network.edges();
    assertThrows(UnsupportedOperationException.class, () -> edges.add(E12));

        assertThrows(IllegalArgumentException.class, () -> InputValidator.validateArrayBounds(null, 0, dst, 0, 10));
        assertThrows(IllegalArgumentException.class, () -> InputValidator.validateArrayBounds(src, 0, null, 0, 10));
        assertThrows(IllegalArgumentException.class, () -> InputValidator.validateArrayBounds(src, -1, dst, 0, 10));

    Set<Integer> nodes = network.nodes();
    assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2));
    addNode(N1);
    assertThat(network.nodes()).containsExactlyElementsIn(nodes);
  }

  @Override
  @Test
  public void edges_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<String> edges = network.edges();
    assertThrows(UnsupportedOperationException.class, () -> edges.add(E12));