cycle.remove();
    assertEquals(singletonList("b"), iterable);
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    cycle.remove();
    assertEquals(emptyList(), iterable);
    assertFalse(cycle.hasNext());
  }

  public void testCycleRemoveWithoutNext() {
    Iterator<String> cycle = Iterators.cycle("a", "b");

            List<String> cycle = visitCycle(graph, Collections.singleton(to), new HashMap<>(), new LinkedList<>());
            if (cycle != null) {
                // remove edge which introduced cycle
                throw new CycleDetectedException(
                        "Edge between '" + from + "' and '" + to + "' introduces to cycle in the graph", cycle);
            }
        }
    }

    cycle.remove();
    assertEquals(singletonList("b"), iterable);
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    cycle.remove();
    assertEquals(emptyList(), iterable);
    assertFalse(cycle.hasNext());
  }

  public void testCycleRemoveWithoutNext() {
    Iterator<String> cycle = Iterators.cycle("a", "b");

        from.children.add(to);
        to.parents.add(from);
        List<String> cycle = findCycle(to);
        if (cycle != null) {
            // remove edge which introduced cycle
            removeEdge(from, to);
            throw new CycleDetectedException(
                    "Edge between '" + from.label + "' and '" + to.label + "' introduces to cycle in the graph", cycle);
        }
    }

    void removeEdge(Vertex from, Vertex to) {

    // always point to "a".
    assertEquals("a", cycle.iterator().next());
  }

  public void testCycle_emptyIterable() {
    FluentIterable<Integer> cycle = FluentIterable.<Integer>of().cycle();
    assertFalse(cycle.iterator().hasNext());
  }

  public void testCycle_removingAllElementsStopsCycle() {
    FluentIterable<Integer> cycle = fluent(1, 2).cycle();
    Iterator<Integer> iterator = cycle.iterator();

       *
       * Maybe there is a way to avoid this cycle. But we think the cycle is safe enough to ignore:
       * Each task is retained for only as long as it is running -- so it's retained only as long as
       * it would already be retained by the underlying executor.
       *
       * If the cycle test starts reporting this cycle in the future, we should add an entry to
       * cycle_suppress_list.txt.
       */

  }

  public void testConcat_infiniteIterable() throws IOException {
    CharSource source = CharSource.wrap("abcd");
    Iterable<CharSource> cycle = Iterables.cycle(ImmutableList.of(source));
    CharSource concatenated = CharSource.concat(cycle);

    String expected = "abcdabcd";

    // read the first 8 chars manually, since there's no equivalent to ByteSource.slice

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.artifact.resolver;

import org.apache.maven.artifact.Artifact;

/**
 * Indicates a cycle in the dependency graph.
 *
 */
public class CyclicDependencyException extends ArtifactResolutionException {
    private Artifact artifact;

    public CyclicDependencyException(String message, Artifact artifact) {

                if (parents.contains(a.getDependencyConflictId())) {
                    a.setDependencyTrail(getDependencyTrail());

                    throw new CyclicDependencyException("A dependency has introduced a cycle", a);
                }

                children.add(new ResolutionNode(a, remoteRepositories, this));
            }
            children = Collections.unmodifiableList(children);
        } else {

    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";
      assertEquals(expected, string);
      if (howManyChecked++ == 5) {
        break;
      }