Path temp = createTempFile();
    assertTrue(Files.exists(temp));
    Files.delete(temp);
    assertFalse(Files.exists(temp));

    MoreFiles.touch(temp);
    assertTrue(Files.exists(temp));
    MoreFiles.touch(temp);
    assertTrue(Files.exists(temp));
  }

  public void testTouchTime() throws IOException {
    Path temp = createTempFile();
    assertTrue(Files.exists(temp));

    /**
     * GETs the source URI content into target (does not have to exist, or will be overwritten if exist). The
     * source MUST BE relative from the {@link RemoteRepository#getUrl()} root.
     *
     * @return {@code true} if operation succeeded, {@code false} if source does not exist.
     * @throws RuntimeException If failed (and not due source not exists).
     */
    boolean get(@Nonnull URI relativeSource, @Nonnull Path target);

  }

  public void testTouch() throws IOException {
    File temp = createTempFile();
    assertTrue(temp.exists());
    assertTrue(temp.delete());
    assertFalse(temp.exists());
    Files.touch(temp);
    assertTrue(temp.exists());
    Files.touch(temp);
    assertTrue(temp.exists());

    assertThrows(
        IOException.class,
        () ->
            Files.touch(

  static final String EDGE_ALREADY_EXISTS = "Edge %s already exists in the graph.";
  static final String ENDPOINTS_MISMATCH =
      "Mismatch: endpoints' ordering is not compatible with directionality of the graph";

  /** Singleton edge value for {@link Graph} implementations backed by {@link ValueGraph}s. */
  enum Presence {
    EDGE_EXISTS
  }

            checkConnection(f);
            f.resolve("test").exists();
        }
    }


    @Test
    public void transportReconnects () throws IOException {
        try ( SmbFile f = getDefaultShareRoot() ) {
            // transport disconnects can happen pretty much any time
            assertNotNull(f);
            f.connect();
            f.exists();
            assertNotNull(f);

        if (opLambda != null) {
            opLambda.callback(builder);
        }
    }

    public void setBoost_Exists() {
        setBoost_Exists(null);
    }

    public void setBoost_Exists(ConditionOptionCall<ExistsQueryBuilder> opLambda) {
        ExistsQueryBuilder builder = regExistsQ("boost");
        if (opLambda != null) {
            opLambda.callback(builder);

    // Exists to test that our framework doesn't run it:
    @SuppressWarnings("unused")
    @ExampleDerivedFeature.Require({
      ExampleDerivedFeature.DERIVED_FEATURE_1,
      ExampleDerivedFeature.DERIVED_FEATURE_2
    })
    public void testRequiringTwoExplicitDerivedFeatures() throws Exception {
      doNotActuallyRunThis();
    }

    // Exists to test that our framework doesn't run it:

                boolean exists = installed.stream().map(this::getArtifactFromMap)
                        .anyMatch(a -> a.getName().equals(target.getName()) && a.getVersion().equals(target.getVersion()));
                if (!exists) {
                    ThreadUtil.sleep(500);
                    continue;
                }
                assertTrue(exists);
                done = true;
                break;

        if (opLambda != null) {
            opLambda.callback(builder);
        }
    }

    public void setEndTime_Exists() {
        setEndTime_Exists(null);
    }

    public void setEndTime_Exists(ConditionOptionCall<ExistsQueryBuilder> opLambda) {
        ExistsQueryBuilder builder = regExistsQ("endTime");
        if (opLambda != null) {

  }

  private interface HierarchyFixtureInterface {
    // Exists only for hierarchy mapping; no members.
  }

  private interface HierarchyFixtureSubinterface extends HierarchyFixtureInterface {
    // Exists only for hierarchy mapping; no members.
  }

  private static class HierarchyFixtureParent implements HierarchyFixtureSubinterface {
    // Exists only for hierarchy mapping; no members.
  }