src/vs/editor/common/model/bracketPairsTextModelPart/bracketPairsTree/bracketPairsTree.ts/BracketPairsTree/handleContentChanged
class BracketPairsTree:	public handleContentChanged(change: IModelContentChangedEvent) {
		const edits = change.changes.map(c => {
			const range = Range.lift(c.range);
			return new TextEditInfo(
				positionToLength(range.getStartPosition()),
				positionToLength(range.getEndPosition()),
				lengthOfString(c.text)
			);
		}).reverse();

		this.astWithTokens = this.parseDocumentFromTextBuffer(edits, this.astWithTokens, false);
		if (this.initialAstWithoutTokens) {
			this.initialAstWithoutTokens = this.parseDocumentFromTextBuffer(edits, this.initialAstWithoutTokens, false);
		}
	}