IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N4, N5, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
    e = assertThrows(IllegalArgumentException.class, () -> addEdge(N2, N1, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
  }

  @Test
  public void addEdge_parallelEdge_notAllowed() {
    assume().that(graphIsMutable()).isTrue();

          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {
        AssertionError error = new AssertionError("malformed class path entry: " + entry);
        error.initCause(e);
        throw error;
      }
    }
    return urls.build().toArray(new URL[0]);
  }

  /** Returns the URLs in the class path. */
  static URL[] getClassPathUrls() {

        waitForInterrupt(currentThread);
      }
      if (run) {
        if (error == null) {
          // The cast is safe because of the `run` and `error` checks.
          afterRanInterruptiblySuccess(uncheckedCastNullableTToT(result));
        } else {
          afterRanInterruptiblyFailure(error);
        }
      }
    }
  }

  private void waitForInterrupt(Thread currentThread) {
    /*

    }

    private static String getMessage(Throwable error, String def) {
        if (error == null) {
            return def;
        }
        String msg = error.getMessage();
        if (msg != null && !msg.isEmpty()) {
            return msg;
        }
        return getMessage(error.getCause(), def);
    }

    private ArtifactRepositoryLayout getLayout(String id) {

          } catch (Exception e) { // sneaky checked exception
            AssertionError error =
                new AssertionFailedError("Serialization failed on return value of " + factory);
            error.initCause(e.getCause());
            throw error;
          } catch (AssertionFailedError e) {
            AssertionError error =
                new AssertionFailedError(

   * reader each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned reader is closed.
   *
   * @throws IOException if an I/O error occurs while opening the reader
   */
  public abstract Reader openStream() throws IOException;

  /**
   * Opens a new {@link BufferedReader} for reading from this source. This method returns a new,

    Object newValue = new Object();
    valueRef.set(newValue);
    assertSame(newValue, cache.getUnchecked(new Object()));
  }

  public void testGetUnchecked_error() {
    final Error cause = new Error();
    final AtomicReference<Object> valueRef = new AtomicReference<>();
    LoadingCache<Object, Object> cache =
        new AbstractLoadingCache<Object, Object>() {
          @Override

        // execute
        ToolchainPrivate[] toolchains = toolchainManager.getToolchainsForType("basic", session);

        // verify
        verify(logger, never()).error(anyString());
        assertEquals(1, toolchains.length);
    }

    @Test
    void testToolchainsForUnknownType() throws Exception {
        // prepare
        MavenSession session = mock(MavenSession.class);

    throw new JudgmentError();
  }

  @Subscribe
  @AllowConcurrentEvents
  public void threadSafeMethod(Object arg) {}

  /** Local Error subclass to check variety of error thrown. */
  class JudgmentError extends Error {

    private static final long serialVersionUID = 634248373797713373L;
  }

   * independent stream each time it is called.
   *
   * <p>The caller is responsible for ensuring that the returned stream is closed.
   *
   * @throws IOException if an I/O error occurs while opening the stream
   */
  public abstract InputStream openStream() throws IOException;

  /**
   * Opens a new buffered {@link InputStream} for reading from this source. The returned stream is