Always raise an error, as this method is not supported without loading the additional NetClients package.
Always evaluate aBlock and answer the result if the additional NetClients package is not loaded. If it is, instead, return a WebEntity with the contents of the resource specified by anURI, and only evaluate the block if loading the resource fails.
Check if aURI can be fetched from the Internet or from the local system, and if so return a Stream with its contents. If this is not possible, raise an exception.
Check if aURI can be fetched from the Internet or from the local system, and if so return a Stream with its contents. If this is not possible, instead, evaluate the zero-argument block aBlock and answer the result of the evaluation.