assume().that(graphIsMutable()).isTrue();
    assume().that(graph.allowsSelfLoops()).isTrue();

    graphAsMutableGraph.putEdge(N1, N1);
    assertThat(graphAsMutableGraph.putEdge(N1, N1)).isFalse();
  }

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

    putEdge(N1, N2);
    putEdge(N2, N1);

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

    }
  }

  /**
   * Verifies that a collection is immutable.
   *
   * <p>A collection is considered immutable if:
   *
   * <ol>
   *   <li>All its mutation methods result in UnsupportedOperationException, and do not change the
   *       underlying contents.
   *   <li>All methods that return objects that can indirectly mutate the collection throw

 * {@link #runOneIteration} that will be executed periodically as specified by its {@link
 * Scheduler}. When this service is asked to stop via {@link #stopAsync} it will cancel the periodic
 * task (but not interrupt it) and wait for it to stop before running the {@link #shutDown} method.
 *
 * <p>Subclasses are guaranteed that the life cycle methods ({@link #runOneIteration}, {@link

  abstract Network<Integer, String> createGraph();

  /**
   * A proxy method that adds the node {@code n} to the graph being tested. In case of Immutable
   * graph implementations, this method should replace {@link #network} with a new graph that
   * includes this node.
   */
  abstract void addNode(Integer n);

  /**
   * A proxy method that adds the edge {@code e} to the graph being tested. In case of Immutable

        assertNotNull(exception);
        assertNull(exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_instanceOf() {
        // Test that exception is instance of RuntimeException
        DictionaryExpiredException exception = new DictionaryExpiredException();
        assertTrue(exception instanceof RuntimeException);
        assertTrue(exception instanceof Exception);

        assertEquals("User is not found: ユーザー名", exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_instanceOfFessSystemException() {
        // Test that FessUserNotFoundException is an instance of FessSystemException
        FessUserNotFoundException exception = new FessUserNotFoundException("testuser");

        assertTrue(exception instanceof FessSystemException);

    }
    return tmp;
  }

  private static long random() {
    return randomSource.nextLong();
  }

  // A random value that cannot be 0 and that is unsigned-less-than or equal
  // to the given dividend, so that we don't have half of our divisions being
  // trivial because the divisor is bigger than the dividend.
  // Using remainder here does not give us a uniform distribution but it should

        decoded.decode(buf);
        assertEquals(expected, decoded.value, "decoded value should match original after masking");
    }

    /**
     * Verify that encode writes the correct little-endian sequence
     * to the buffer and that alignment is respected.
     */
    @Test
    void encodeWritesCorrectBytesAndAlignment() throws NdrException {
        NdrShort ns = new NdrShort(0xABCD); // value & 0xFF => 0xCD

     * an Atom file, RSS file or a simple text file.
     */
    private String loc;

    /**
     * Identifies the time that the corresponding Sitemap file was modified. It
     * does not correspond to the time that any of the pages listed in that
     * Sitemap were changed. The value for the lastmod tag should be in W3C
     * Datetime format.
     *