do not expose strings map, because key access was not type checked.

bin/kdbx.dart

@@ -4,6 +4,7 @@ import 'dart:typed_data';
 
 import 'package:args/args.dart';
 import 'package:args/command_runner.dart';
+import 'package:kdbx/kdbx.dart';
 import 'package:kdbx/src/crypto/protected_value.dart';
 import 'package:kdbx/src/kdbx_format.dart';
 import 'package:kdbx/src/kdbx_group.dart';
@@ -108,9 +109,9 @@ class CatCommand extends KdbxFileCommand {
       catGroup(group, depth: depth + 1);
     }
     for (final entry in group.entries) {
-      final value = entry.strings['Password'];
+      final value = entry.getString(KdbxKey('Password'));
       print(
-          '$indent `- ${entry.strings['Title']?.getText()}: ${forceDecrypt ? value?.getText() : value?.toString()}');
+          '$indent `- ${entry.getString(KdbxKey('Title'))?.getText()}: ${forceDecrypt ? value?.getText() : value?.toString()}');
     }
   }
 }

lib/src/kdbx_entry.dart

@@ -1,4 +1,3 @@
-import 'package:collection/collection.dart';
 import 'package:kdbx/src/crypto/protected_value.dart';
 import 'package:kdbx/src/kdbx_consts.dart';
 import 'package:kdbx/src/kdbx_format.dart';
@@ -42,7 +41,7 @@ class KdbxEntry extends KdbxObject {
   XmlElement toXml() {
     final el = super.toXml();
     el.children.removeWhere((e) => e is XmlElement && e.name.local == 'String');
-    el.children.addAll(strings.entries.map((stringEntry) {
+    el.children.addAll(stringEntries.map((stringEntry) {
       final value = XmlElement(XmlName('Value'));
       if (stringEntry.value is ProtectedValue) {
         value.attributes.add(XmlAttribute(XmlName('Protected'), 'true'));
@@ -64,7 +63,11 @@ class KdbxEntry extends KdbxObject {
   KdbxGroup parent;
   final Map<KdbxKey, StringValue> _strings = {};
 
-  Map<KdbxKey, StringValue> get strings => UnmodifiableMapView(_strings);
+//  Map<KdbxKey, StringValue> get strings => UnmodifiableMapView(_strings);
+
+  Iterable<MapEntry<KdbxKey, StringValue>> get stringEntries => _strings.entries;
+
+  StringValue getString(KdbxKey key) => _strings[key];
 
   void setString(KdbxKey key, StringValue value) {
     _strings[key] = value;

lib/src/kdbx_xml.dart

@@ -58,6 +58,11 @@ abstract class KdbxSubTextNode<T> extends KdbxSubNode<T> {
     }
     el.children.add(XmlText(stringValue));
   }
+
+  @override
+  String toString() {
+    return '$runtimeType{${_opt(name)?.text}}';
+  }
 }
 
 class IntNode extends KdbxSubTextNode<int> {

test/kdbx_test.dart

@@ -66,7 +66,7 @@ void main() {
 //      print(ByteUtils.toHexList(saved));
 
       final kdbx = KdbxFormat.read(saved, credentials);
-      expect(kdbx.body.rootGroup.entries.first.strings[KdbxKey('Password')].getText(), 'LoremIpsum');
+      expect(kdbx.body.rootGroup.entries.first.getString(KdbxKey('Password')).getText(), 'LoremIpsum');
       File('test.kdbx').writeAsBytesSync(saved);
     });
   });