DATACASS-486 - Use unique property names in UDT reference documentation example.

src/main/asciidoc/reference/mapping.adoc

@@ -318,12 +318,11 @@ public class Person {
     return ssn;
   }
 
-// other getters/setters ommitted
+  // other getters/setters ommitted
 }
 ----
 ====
 
-
 .Mapped User-Defined type `Address`
 ====
 [source,java]
@@ -334,14 +333,14 @@ public class Address {
   private String city;
 
   @CassandraType(type = Name.VARCHAR)
-  private String city;
+  private String street;
 
   private Set<String> zipcodes;
 
   @CassandraType(type = Name.SET, typeArguments = Name.BIGINT)
   private List<Long> timestamps;
 
-// other getters/setters ommitted
+  // other getters/setters ommitted
 }
 ----
 ====