import java.util.Collections;
import java.util.List;

import org.junit.jupiter.api.Test;

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

public class GraphTest {

    @Test
    void testCycle() throws Graph.CycleDetectedException {
        Graph graph = new Graph();
        graph.addEdge("a1", "a2");
        assertThrows(Graph.CycleDetectedException.class, () -> graph.addEdge("a2", "a1"));
    }

    @Test

    assertEquals("[]", FluentIterable.<String>of().toString());

    assertEquals(
        "[yam, bam, jam, ham]", FluentIterable.from(asList("yam", "bam", "jam", "ham")).toString());
  }

  public void testCycle() {
    FluentIterable<String> cycle = FluentIterable.from(asList("a", "b")).cycle();

    int howManyChecked = 0;
    for (String string : cycle) {
      String expected = (howManyChecked % 2 == 0) ? "a" : "b";

    List<String> expected = asList("1", "2", "null", "3");
    assertEquals(expected, actual);
  }

  // Far less exhaustive than the tests in IteratorsTest
  public void testCycle() {
    Iterable<String> cycle = Iterables.cycle("a", "b");

    int howManyChecked = 0;
    for (String string : cycle) {
      String expected = (howManyChecked % 2 == 0) ? "a" : "b";