code: public ReplicationResult trigger() {
          assertNotEmpty(source, "Source");
          assertNotEmpty(target, "Target");
          InputStream response = null;
          try {
              JsonObject json = createJson();
              if (log.isLoggable(Level.FINE)) {
                  log.fine(json.toString());
              }
  
              final URI uri = new DatabaseURIHelper(client.getBaseUri()).path("_replicate").build();
              response = client.post(uri, json.toString());
              final InputStreamReader reader = new InputStreamReader(response, "UTF-8");
              return client.getGson().fromJson(reader, ReplicationResult.class);
          } catch (UnsupportedEncodingException e) {
              // This should never happen as every implementation of the java platform is required
              // to support UTF-8.
              throw new RuntimeException(e);
          } finally {
              close(response);
          }
      }
docs: Triggers a replication request.