src/vs/editor/common/model/bracketPairsTextModelPart/bracketPairsTree/ast.ts/PairAstNode/constructor
class PairAstNode:	private constructor(
		length: Length,
		public readonly openingBracket: BracketAstNode,
		public readonly child: AstNode | null,
		public readonly closingBracket: BracketAstNode | null,
		public readonly missingOpeningBracketIds: SmallImmutableSet<OpeningBracketId>
	) {
		super(length);
	}