code: public boolean checkExistence(String resourceGroupName, String deploymentName) {
          return checkExistenceWithServiceResponseAsync(resourceGroupName, deploymentName).toBlocking().single().body();
      }
docs: Checks whether the deployment exists.
  
  @param resourceGroupName The name of the resource group with the deployment to check. The name is case insensitive.
  @param deploymentName The name of the deployment to check.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the boolean object if successful.