void getAllByNameRejectsNullOrEmptyHostname() {
        assertThrows(UnknownHostException.class, () -> UniAddress.getAllByName("", false),
                "getAllByName should throw UnknownHostException for empty string");
        assertThrows(UnknownHostException.class, () -> UniAddress.getAllByName(null, false),
                "getAllByName should throw UnknownHostException for null name");
    }

        // getFirstAddress branch: host given and path non-root -> possibleNTDomain=false
        when(nsc.getAllByName(eq("server"), eq(false))).thenReturn(new Address[] { addr });
        SmbResourceLocatorImpl workgroupLike = locator("smb://server/");
        // path is "/" -> triggers possibleNTDomainOrWorkgroup true
        when(nsc.getAllByName(eq("server"), eq(true))).thenReturn(new Address[] { addr });
        assertTrue(workgroupLike.isWorkgroup());

        boolean possibleNTDomainOrWorkgroup = true;
        Address[] expectedAddresses = { mock(Address.class) };
        when(nameServiceClient.getAllByName(hostname, possibleNTDomainOrWorkgroup)).thenReturn(expectedAddresses);

        // Act
        Address[] actualAddresses = nameServiceClient.getAllByName(hostname, possibleNTDomainOrWorkgroup);

        // Assert
        assertNotNull(actualAddresses);

   */
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>

  companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

     */

    public static UniAddress getByName(final String hostname, final boolean possibleNTDomainOrWorkgroup) throws UnknownHostException {
        final UniAddress[] addrs = UniAddress.getAllByName(hostname, possibleNTDomainOrWorkgroup);
        return addrs[0];
    }

    /**
     * Resolves all addresses for the given hostname.
     *
     * @param hostname the hostname to resolve

    @Override
    public UniAddress getByName(final String hostname, final boolean possibleNTDomainOrWorkgroup) throws UnknownHostException {
        return getAllByName(hostname, possibleNTDomainOrWorkgroup)[0];
    }

    @Override
    public UniAddress[] getAllByName(final String hostname, final boolean possibleNTDomainOrWorkgroup) throws UnknownHostException {
        if (hostname == null || hostname.length() == 0) {

                    }
                } else if (path.length() == 0 || path.equals("/")) {
                    this.addresses = this.ctx.getNameServiceClient().getAllByName(host, true);
                } else {
                    this.addresses = this.ctx.getNameServiceClient().getAllByName(host, false);
                }

        when(addr1.getHostAddress()).thenReturn("10.0.0.1");

        Address addr2 = mock(Address.class);
        when(addr2.getHostAddress()).thenReturn("10.0.0.2");

        when(nameSvc.getAllByName(eq("test.server"), eq(true))).thenReturn(new Address[] { addr1, addr2 });

        // Set fail counts (addr1 has more failures, addr2 has fewer)
        pool.failCounts.put("10.0.0.1", 5);

     * @throws UnknownHostException if the host name cannot be resolved
     */
    @Override
    public InetAddress[] resolve(final String host) throws UnknownHostException {
        return InetAddress.getAllByName(toAscii(host));
    }

    /**
     * Decodes the given host string using the specified encoding.
     *
     * @param host the host string to decode
     * @return the decoded host string
     */

```kotlin
val client = OkHttpClient.Builder()
    .dns { hostname -> InetAddress.getAllByName(hostname).toList() }
    .build()
```

Kotlin calling OkHttp 4.x:

```kotlin
val client = OkHttpClient.Builder()
    .dns(object : Dns {
      override fun lookup(hostname: String) =
          InetAddress.getAllByName(hostname).toList()
    })
    .build()
```

SAM conversion impacts these APIs: