/**
   * Removes {@code node} if it is present; all edges incident to {@code node} will also be removed.
   *
   * @return {@code true} if the network was modified as a result of this call
   */
  @CanIgnoreReturnValue
  boolean removeNode(N node);

  /**
   * Removes {@code edge} from this network, if it is present.
   *

                result += "Not listening for calling name";
                break;
            case CALLED_NOT_PRESENT:
                result += "Called name not present";
                break;
            case NO_RESOURCES:
                result += "Called name present, but insufficient resources";
                break;
            case UNSPECIFIED:
                result += "Unspecified error";

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    int initialSize = getMap().size();
    assertEquals("remove(present) should return the associated value", v0(), getMap().remove(k0()));
    assertEquals(
        "remove(present) should decrease a map's size by one.", initialSize - 1, getMap().size());
    expectMissing(e0());
  }

        sets[i] = ImmutableSet.of();
      } else if (setSize < emptySetProportion + singletonSetProportion) {
        sets[i] = ImmutableSet.of(PRESENT);
      } else {
        sets[i] = ImmutableSet.of(PRESENT, new Object());
      }

      if (rng.nextDouble() < hitRate) {
        queries[i] = PRESENT;
      } else {
        queries[i] = ABSENT;
      }
    }
  }

  @Benchmark
  public boolean contains(int reps) {

  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPut_unsupportedPresentExistingValue() {
    try {
      assertEquals("put(present, existingValue) should return present or throw", v0(), put(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)

                        result += "Not listening for calling name";
                        break;
                    case CALLED_NOT_PRESENT:
                        result += "Called name not present";
                        break;
                    case NO_RESOURCES:
                        result += "Called name present, but insufficient resources";
                        break;
                    case UNSPECIFIED:

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_unsupportedPresentExistingValue() {
    try {
      assertEquals(
          "putIfAbsent(present, existingValue) should return present or throw",
          v0(),
          putIfAbsent(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_unsupportedPresentExistingValue() {
    try {
      assertEquals(
          "putIfAbsent(present, existingValue) should return present or throw",
          v0(),
          getMap().putIfAbsent(k0(), v0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

        return map.containsKey(o);
    }

    @Override
    public boolean add(final String o) {
        return map.put(o, PRESENT) == null;
    }

    @Override
    public boolean remove(final Object o) {
        return map.remove(o) == PRESENT;
    }

    @Override
    public void clear() {
        map.clear();
    }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    int initialSize = collection.size();
    assertTrue("remove(present) should return true", collection.remove(e0()));
    assertEquals(
        "remove(present) should decrease a collection's size by one.",
        initialSize - 1,
        collection.size());
    expectMissing(e0());
  }