if (domains == null) {
            return false;
        }
        domain = domain.toLowerCase();
        return domains.get(domain) != null;
    }

    /**
     * Gets a domain controller transport for the specified domain
     * @param domain the domain name
     * @param auth the authentication credentials
     * @return an SMB transport to the domain controller

                    this.domains = new LsarTrustInformation[_domainss];
                }
                _src = _src.derive(_domainsi);
                for (int _i = 0; _i < _domainss; _i++) {
                    if (this.domains[_i] == null) {
                        this.domains[_i] = new LsarTrustInformation();
                    }
                    this.domains[_i].decode(_src);
                }
            }
        }
    }

        synchronized (this.domainsLock) {
            final Map<String, Map<String, CacheEntry<DfsReferralDataInternal>>> domains = getTrustedDomains(tf);
            if (domains == null) {
                return false;
            }
            domain = domain.toLowerCase(Locale.ROOT);
            return domains.get(domain) != null;
        }
    }

                    domains = new LsarTrustInformation[_domainss];
                }
                _src = _src.derive(_domainsi);
                for (int _i = 0; _i < _domainss; _i++) {
                    if (domains[_i] == null) {
                        domains[_i] = new LsarTrustInformation();
                    }
                    domains[_i].decode(_src);
                }
            }
        }
    }

    /**

            }
            rpc.domains = new lsarpc.LsarRefDomainList();
            rpc.domains.count = 1;
            rpc.domains.max_count = 1;
            rpc.domains.domains = new lsarpc.LsarTrustInformation[1];
            rpc.domains.domains[0] = new lsarpc.LsarTrustInformation();
            rpc.domains.domains[0].name = new UnicodeString("", false);
            rpc.domains.domains[0].sid = new jcifs.dcerpc.rpc.sid_t();

				}
				for _, addr := range addrs {
					domainIPs.Add(addr)
				}
			}
			domainIPs.Add(endpoint)
		}
		updateDomainIPs(domainIPs)
	} else {
		// Add found interfaces IP address to global domain IPS,
		// loopback addresses will be naturally dropped.
		domainIPs := mustGetLocalIP4()
		for _, host := range globalEndpoints.Hostnames() {
			domainIPs.Add(host)
		}
		updateDomainIPs(domainIPs)
	}

* **TCP doesn't know about "domains"**. Only about IP addresses.
    * The information about the **specific domain** requested goes in the **HTTP data**.
* The **HTTPS certificates** "certify" a **certain domain**, but the protocol and encryption happen at the TCP level, **before knowing** which domain is being dealt with.

    }

    @ParameterizedTest
    @MethodSource("domains")
    @DisplayName("getUserDomain handles null and empty")
    void getUserDomain_edges(String domain) {
        TestCredentials creds = new TestCredentials(domain, false, false, new Subject(), false);
        assertEquals(domain, creds.getUserDomain());
    }

    static Stream<String> domains() {
        return Stream.of(null, "", "SALES");
    }

            this.domainName = domainNameString.check(pacStream.readString());

            // ID for domain (used with relative IDs to get SIDs)
            SID domainId = null;
            if (domainIdPointer != 0) {
                domainId = pacStream.readSid();
            }

            // Extra SIDs data
            PacSidAttributes[] extraSidAtts = {};

   * </ul>
   *
   * @param domain A domain name (not IP address)
   * @throws IllegalArgumentException if {@code domain} is not syntactically valid according to
   *     {@link #isValid}
   * @since 10.0 (previously named {@code fromLenient})
   */
  @CanIgnoreReturnValue // TODO(b/219820829): consider removing
  public static InternetDomainName from(String domain) {
    return new InternetDomainName(checkNotNull(domain));