code: public Observable<List<DatabaseInner>> listByClusterAsync(String resourceGroupName, String clusterName) {
          return listByClusterWithServiceResponseAsync(resourceGroupName, clusterName).map(new Func1<ServiceResponse<List<DatabaseInner>>, List<DatabaseInner>>() {
              @Override
              public List<DatabaseInner> call(ServiceResponse<List<DatabaseInner>> response) {
                  return response.body();
              }
          });
      }
docs: Returns the list of databases of the given Kusto cluster.
  
  @param resourceGroupName The name of the resource group containing the Kusto cluster.
  @param clusterName The name of the Kusto cluster.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;DatabaseInner&gt; object