src/vs/workbench/contrib/tasks/browser/terminalTaskSystem.ts/TerminalTaskSystem/_resolveVariable
class TerminalTaskSystem:	private async _resolveVariable(resolver: VariableResolver, value: CommandString | undefined): Promise<CommandString> {
		// TODO@Dirk Task.getWorkspaceFolder should return a WorkspaceFolder that is defined in workspace.ts
		if (Types.isString(value)) {
			return resolver.resolve(value);
		} else if (value !== undefined) {
			return {
				value: await resolver.resolve(value.value),
				quoting: value.quoting
			};
		} else { // This should never happen
			throw new Error('Should never try to resolve undefined.');
		}
	}