import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of {@link Multimap} using hash tables.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *

   *
   * <p>If {@code edge} already connects an endpoint pair equal to {@code endpoints}, then this
   * method will have no effect.
   *
   * @return {@code true} if the network was modified as a result of this call
   * @throws IllegalArgumentException if {@code edge} already exists in the graph and connects some
   *     other endpoint pair that is not equal to {@code endpoints}

      }

    /**
     * Sets the public/private key pair used for this certificate. If unset a key pair will be
     * generated.
     */
    fun keyPair(keyPair: KeyPair) =
      apply {
        this.keyPair = keyPair
      }

    /**
     * Sets the public/private key pair used for this certificate. If unset a key pair will be
     * generated.
     */
    fun keyPair(

 * The version selection is done for each dependency during the collection phase.
 * The flatten phase will keep only a single version per ({@code groupId}, {@code artifactId}) pair.
 * The resolution will actually download the dependencies (or artifacts) that have been computed.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface Dependency extends Artifact {
    /**

  fun testDnsRequest() {
    val (allAddresses, exception) = dnsQuery("localhost")

    assertThat(exception).isNull()
    assertThat(allAddresses).isNotEmpty()
  }

  private fun dnsQuery(hostname: String): Pair<List<InetAddress>, Exception?> {
    val allAddresses = mutableListOf<InetAddress>()
    var exception: Exception? = null
    val latch = CountDownLatch(1)

    // assumes an IPv4 address

	}

	// check for proceeding surrogate pair
	c = d.next()
	if !utf16.IsSurrogate(r) || c != '\\' {
		d.scratch.addRune(r)
		goto scan
	}
	if c = d.next(); c != 'u' {
		d.scratch.addRune(r)
		goto scan_esc
	}

	r2 := d.u4()
	if r2 < 0 {
		return "", d.mkError(ErrSyntax, "in unicode escape sequence")
	}

	// write surrogate pair
	d.scratch.addRune(utf16.DecodeRune(r, r2))

            }
        }
    }

    /**
     * @return the source file and it's source root
     */
    fun sourceFileAndSourceRootFor(sourceFilePath: String): Pair<File, File> =
        sourceRoots.asSequence()
            .map { it.resolve(sourceFilePath) to it }
            .firstOrNull { it.first.isFile }

    assertStringHash(0xb5a4be05, "ABCDefGHI\u0799", UTF_8);
    assertStringHash(0xfc5ba834, "毎月１日,毎週月曜日", UTF_8);
    assertStringHash(0x8a5c3699, "surrogate pair: \uD83D\uDCB0", UTF_8);

    assertStringHash(0, "", UTF_16LE);
    assertStringHash(0x288418e4, "k", UTF_16LE);
    assertStringHash(0x5a0cb7c3, "hell", UTF_16LE);
    assertStringHash(0xd7c31989, "hello", UTF_16LE);

   *
   * <p>If {@code edge} already connects an endpoint pair equal to {@code endpoints}, then this
   * method will have no effect.
   *
   * @return {@code true} if the network was modified as a result of this call
   * @throws IllegalArgumentException if {@code edge} already exists in the graph and connects some
   *     other endpoint pair that is not equal to {@code endpoints}

          inv.containsValue(reversed.getValue()));
      /*
       * TODO(cpovirk): This is a bit stronger than super.expectMissing(), which permits a <key,
       * someOtherValue> pair.
       */
      assertNull(
          "Inverse should not return a mapping for key " + reversed.getKey(),
          inv.get(reversed.getKey()));
    }
  }