src/vs/editor/common/languages/supports/electricCharacter.ts/BracketElectricCharacterSupport/getElectricCharacters
class BracketElectricCharacterSupport:	public getElectricCharacters(): string[] {
		const result: string[] = [];

		if (this._richEditBrackets) {
			for (const bracket of this._richEditBrackets.brackets) {
				for (const close of bracket.close) {
					const lastChar = close.charAt(close.length - 1);
					result.push(lastChar);
				}
			}
		}

		return distinct(result);
	}