code: @Beta
      public Type getCustomEventMapping(final String eventType) {
          if (!containsCustomEventMappingFor(eventType)) {
              return null;
          } else {
              return this.eventTypeToEventDataMapping.get(canonicalizeEventType(eventType));
          }
      }
docs: Get type of the Java model that is mapped to the given eventType.
  
  @param eventType the event type name.
  @return type of the Java model if mapping exists, null otherwise.