code: @Nonnull
      public DeploymentNode addDeploymentNode(@Nonnull String name, String description, String technology, int instances, Map<String, String> properties) {
          return addDeploymentNode(DeploymentElement.DEFAULT_DEPLOYMENT_ENVIRONMENT, name, description, technology, instances, properties);
      }
docs: Adds a top-level deployment node to this model.
  
  @param name        the name of the deployment node
  @param description the description of the deployment node
  @param technology  the technology associated with the deployment node
  @param instances   the number of instances of the deployment node
  @param properties  a map of name/value properties associated with the deployment node
  @return a DeploymentNode instance
  @throws IllegalArgumentException if the name is not specified, or a top-level deployment node with the same name already exists in the model