         let filePrefix = namer.typePrefix(forFile: fileDescriptor)
         p.print(
           "\n",
+          "// MARK: - File's ExtensionMap: \(filePrefix)\(filenameAsIdentifer)_Extensions\n",
+          "\n",
           "/// A `SwiftProtobuf.SimpleExtensionMap` that includes all of the extensions defined by\n",
           "/// this .proto file. It can be used any place an `SwiftProtobuf.ExtensionMap` is needed\n",
           "/// in parsing, or it can be combined with other `SwiftProtobuf.SimpleExtensionMap`s to create\n",

    func generateMessageSwiftExtensions(printer p: inout CodePrinter) {
        guard !extensions.isEmpty else { return }

        // Reorder the list so they are grouped by the Message being extended, but
        // maintaining the order they were within the file within those groups.
        let grouped: [ExtensionGenerator] = extensions.enumerated().sorted {


    func generateProtobufExtensionDeclarations(printer p: inout CodePrinter) {
      guard !extensions.isEmpty else { return }

      p.print(
          "\n",
          "// Extension Objects - The only reason these might be needed is when manually\n",
          "// constructing a `SimpleExtensionMap`, otherwise, use the above _Extension Properties_\n",
          "// accessors for the extension fields on the messages directly.\n")

      func endScope() {
          p.outdent()
