src/vs/editor/common/languages/languageConfiguration.ts/StandardAutoClosingPairConditional/findNeutralCharacter
class StandardAutoClosingPairConditional:	public findNeutralCharacter(): string | null {
		if (!this._neutralCharacterSearched) {
			this._neutralCharacterSearched = true;
			if (!this._neutralCharacter) {
				this._neutralCharacter = this._findNeutralCharacterInRange(CharCode.Digit0, CharCode.Digit9);
			}
			if (!this._neutralCharacter) {
				this._neutralCharacter = this._findNeutralCharacterInRange(CharCode.a, CharCode.z);
			}
			if (!this._neutralCharacter) {
				this._neutralCharacter = this._findNeutralCharacterInRange(CharCode.A, CharCode.Z);
			}
		}
		return this._neutralCharacter;
	}