Don't return null for getDomain()

Author: oschwald

CHANGELOG.md

@@ -26,6 +26,8 @@ CHANGELOG
   `IpAddress.getCountry()` now returns a `com.maxmind.geoip2.record.Country`.
 * Removed deprecated `Payment.Processor.VERAPAY` enum value. Use `VEREPAY`
   instead.
+* `Email.getDomain()` will now return an empty object rather than null if
+  there is no domain data. This is match other response model class getters.
 * Upgraded the `geoip2` dependency to 2.16.1. This adds mobile country code
   (MCC) and mobile network code (MNC) to minFraud Insights and Factors
   responses. These are available at

src/main/java/com/maxmind/minfraud/response/Email.java

@@ -30,15 +30,15 @@ public Email(
             @JsonProperty("is_high_risk") Boolean isHighRisk,
             @JsonProperty("first_seen") String firstSeen
     ) {
-        this.domain = domain;
+        this.domain = domain == null ? new EmailDomain() : domain;
         this.isDisposable = isDisposable;
         this.isFree = isFree;
         this.isHighRisk = isHighRisk;
         this.firstSeen = firstSeen;
     }
 
     public Email() {
-        this(null, null, null);
+        this(null, null, null, null, null);
     }
 
     /**

src/main/java/com/maxmind/minfraud/response/EmailDomain.java

@@ -17,6 +17,10 @@ public EmailDomain(
         this.firstSeen = firstSeen;
     }
 
+    public EmailDomain() {
+        this(null);
+    }
+
     /**
      * @return A date to identify the date an email domain was first
      * seen by MaxMind.

src/test/java/com/maxmind/minfraud/response/EmailTest.java

@@ -48,6 +48,7 @@ public void testEmailWithoutFirstSeen() throws Exception {
                         .finish()
         );
 
+        assertNotNull(email.getDomain());
         assertNull(email.isDisposable());
         assertFalse(email.isFree());
         assertTrue(email.isHighRisk());