src/vs/editor/common/model/bracketPairsTextModelPart/bracketPairsTree/bracketPairsTree.ts/BracketPairsTree/handleDidChangeBackgroundTokenizationState
class BracketPairsTree:	public handleDidChangeBackgroundTokenizationState(): void {
		if (this.textModel.tokenization.backgroundTokenizationState === BackgroundTokenizationState.Completed) {
			const wasUndefined = this.initialAstWithoutTokens === undefined;
			// Clear the initial tree as we can use the tree with token information now.
			this.initialAstWithoutTokens = undefined;
			if (!wasUndefined) {
				this.didChangeEmitter.fire();
			}
		}
	}