src/vs/workbench/api/common/extHostLanguageFeatures.ts/InlineCompletionController/get
class InlineCompletionController:	public static get<T extends vscode.InlineCompletionItem>(provider: vscode.InlineCompletionItemProvider<T>): InlineCompletionController<T> {
		let existing = InlineCompletionController.map.get(provider);
		if (!existing) {
			existing = new InlineCompletionController();
			InlineCompletionController.map.set(provider, existing);
		}
		return existing;
	}