extensions/typescript-language-features/src/languageFeatures/completions.ts/MyCompletionItem/getCommitCharacters
class MyCompletionItem:	private static getCommitCharacters(context: CompletionContext, entry: Proto.CompletionEntry): string[] | undefined {
		if (entry.kind === PConst.Kind.warning) { // Ambient JS word based suggestion
			return undefined;
		}

		if (context.isNewIdentifierLocation || !context.isInValidCommitCharacterContext) {
			return undefined;
		}

		const commitCharacters: string[] = ['.', ',', ';'];
		if (context.enableCallCompletions) {
			commitCharacters.push('(');
		}

		return commitCharacters;
	}