import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

public class GraphTest {

    @Test
    public void testGraph() throws CycleDetectedException {
        Graph graph = new Graph();
        graph.addVertex("a");
        assertEquals(1, graph.getVertices().size());
        assertEquals("a", graph.getVertex("a").getLabel());

  public void testIsWrapperType() {
    assertThat(Primitives.isWrapperType(Void.class)).isTrue();
    assertThat(Primitives.isWrapperType(void.class)).isFalse();
  }

  public void testWrap() {
    assertThat(Primitives.wrap(int.class)).isEqualTo(Integer.class);
    assertThat(Primitives.wrap(Integer.class)).isEqualTo(Integer.class);
    assertThat(Primitives.wrap(String.class)).isEqualTo(String.class);
  }

      return input.length();
    }
  }

  private static final Equivalence<String> LENGTH_EQUIVALENCE =
      Equivalence.equals().onResultOf(LengthFunction.INSTANCE);

  public void testWrap() {
    new EqualsTester()
        .addEqualityGroup(
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("world"))