code: public void deleteComputeNodeUser(String poolId, String nodeId, String userName) throws BatchErrorException, IOException {
          deleteComputeNodeUser(poolId, nodeId, userName, null);
      }
docs: Deletes the specified user account from the specified compute node.
  
  @param poolId The ID of the pool that contains the compute node.
  @param nodeId The ID of the compute node where the user account will be deleted.
  @param userName The name of the user account to be deleted.
  @throws BatchErrorException Exception thrown when an error response is received from the Batch service.
  @throws IOException Exception thrown when there is an error in serialization/deserialization of data sent to/received from the Batch service.