// HpD API plugin invoked from Project page:

Project project = api.CurrentProject ?? throw new Exception();

// Create new variant in the silent mode.
Variant variant = project.CreateVariant("NewVariant", silent: true);

// The new variant is not shown in the project structure for now.

// Creating multiple documents at once without refreshing project structure after each document:
// Set the variant to the silent mode (or open it in the silent mode).
variant.SilentMode = true;
					
// Create documents.
for (int i = 0; i < 50; i++)
{
	variant.CreateWorkspace($"Workspace{i}");
}
					
// There is still no new document shown in project structure in UI.
					
// Refresh the project structure only once at the end.
project.UpdateProjectStructure();
					
// New variant and all its new documents are shown in the project structure now.