fixup! feat!: rework TD @context handling

test/core/context_test.dart

@@ -0,0 +1,23 @@
+// Copyright 2024 Contributors to the Eclipse Foundation. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+import "package:dart_wot/core.dart";
+import "package:dart_wot/src/core/definitions/context.dart";
+import "package:test/test.dart";
+
+void main() {
+  group("Thing Description @context should", () {
+    test("not allow for an invalid first entry", () {
+      final illegalSingleContextEntry =
+          SingleContextEntry.fromString("https://example.com");
+
+      expect(
+        () => Context([illegalSingleContextEntry]),
+        throwsA(isA<ValidationException>()),
+      );
+    });
+  });
+}