code: public Observable<ReplicationLinkInner> getAsync(String resourceGroupName, String serverName, String databaseName, String linkId) {
          return getWithServiceResponseAsync(resourceGroupName, serverName, databaseName, linkId).map(new Func1<ServiceResponse<ReplicationLinkInner>, ReplicationLinkInner>() {
              @Override
              public ReplicationLinkInner call(ServiceResponse<ReplicationLinkInner> response) {
                  return response.body();
              }
          });
      }
docs: Gets a database replication link.
  
  @param resourceGroupName The name of the resource group that contains the resource. You can obtain this value from the Azure Resource Manager API or the portal.
  @param serverName The name of the server.
  @param databaseName The name of the database to get the link for.
  @param linkId The replication link ID to be retrieved.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the ReplicationLinkInner object