code: public Observable<RestorableDroppedDatabaseInner> getAsync(String resourceGroupName, String serverName, String restorableDroppededDatabaseId) {
          return getWithServiceResponseAsync(resourceGroupName, serverName, restorableDroppededDatabaseId).map(new Func1<ServiceResponse<RestorableDroppedDatabaseInner>, RestorableDroppedDatabaseInner>() {
              @Override
              public RestorableDroppedDatabaseInner call(ServiceResponse<RestorableDroppedDatabaseInner> response) {
                  return response.body();
              }
          });
      }
docs: Gets a deleted database that can be restored.
  
  @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 restorableDroppededDatabaseId The id of the deleted database in the form of databaseName,deletionTimeInFileTimeFormat
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the RestorableDroppedDatabaseInner object