The workspace to search for the variable. It may be a flyout workspace or main workspace.
The ID to use to look up or create the variable, or null.
Optionalopt_name: stringThe string to use to look up or create the variable.
Optionalopt_type: stringThe type to use to look up or create the variable.
The variable corresponding to the given ID or name + type combination.
Helper function to look up or create a variable on the given workspace. If no variable exists, creates and returns it.