     }
   }
 
+  /// Enqueues the given list of formatting tokens between each element of the given syntax
+  /// collection (but not before the first one nor after the last one).
   private func insertTokens<Node: SyntaxCollection>(
     _ tokens: Token...,
     betweenElementsOf collectionNode: Node


private let rangeOperators: Set = ["...", "..<"]

private final class TokenStreamCreator: SyntaxVisitor {
  private var tokens = [Token]()
  private var beforeMap = [TokenSyntax: [Token]]()


  var openings = 0

  /// If the syntax token is non-nil, enqueue the given list of formatting tokens before it in the
  /// token stream.
  func before(_ token: TokenSyntax?, tokens: Token...) {
    before(token, tokens: tokens)
  }

  /// If the syntax token is non-nil, enqueue the given list of formatting tokens before it in the
  /// token stream.
  func before(_ token: TokenSyntax?, tokens: [Token]) {
    guard let tok = token else { return }
    for preToken in tokens {
