return new TestCollection() {
            @Override
            protected void visitChildren(Consumer<FileCollectionInternal> visitor) {
                visitor.accept(TestFiles.fileCollectionFactory().fixed(files))
            }
        }
    }

    def "visits contents on each query"() {
        def visited = 0;
        def collection = new TestCollection() {
            @Override

            } else {
                new File(entry) // do not create
            }
        }
        new TestCollection(files)
    }

    private static class TestCollection extends AbstractFileCollection {
        private Set<File> entries

        private TestCollection(Set<File> entries) {
            this.entries = entries
        }
        @Override
        String getDisplayName() {

        then:
        1 * input1.cleanupValue()
        1 * input3.cleanupValue()
    }

    def "notifies calculated files of task start and complete"() {
        def calculated = Mock(TestCollection)
        def fileCollection = new CalculatedTaskInputFileCollection(taskDependencyFactory, ":task", calculated)

        when:
        fileCollection.prepareValue()

        then:

  }

  public void testImmutableSortedMultiset() {
    assertFreshInstance(new TypeToken<ImmutableSortedMultiset<String>>() {});
  }

  public void testCollection() {
    assertFreshInstance(new TypeToken<Collection<String>>() {});
  }

  public void testIterable() {
    assertFreshInstance(new TypeToken<Iterable<String>>() {});
  }

  public void testMap() {

  }

  public void testImmutableSortedMultiset() {
    assertFreshInstance(new TypeToken<ImmutableSortedMultiset<String>>() {});
  }

  public void testCollection() {
    assertFreshInstance(new TypeToken<Collection<String>>() {});
  }

  public void testIterable() {
    assertFreshInstance(new TypeToken<Iterable<String>>() {});
  }

  public void testMap() {