src/vs/editor/common/languages/supports/indentRules.ts/IndentRulesSupport/shouldDecrease
class IndentRulesSupport:	public shouldDecrease(text: string): boolean {
		if (this._indentationRules && this._indentationRules.decreaseIndentPattern && resetGlobalRegex(this._indentationRules.decreaseIndentPattern) && this._indentationRules.decreaseIndentPattern.test(text)) {
			return true;
		}
		return false;
	}