fix NamespacesExampleTest: Refactor headerValueEncode to use toText for string conversion (#2967)

* Update XPath expression to ensure string conversion for `id` header

* Refactor `headerValueEncode` to use `toText` for string conversion and simplify XPath in proxies.xml

Author: christiangoerdes

core/src/main/java/com/predic8/membrane/core/interceptor/llmgateway/NullPolicies.java

@@ -1,3 +1,17 @@
+/* Copyright 2026 predic8 GmbH, www.predic8.com
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
 package com.predic8.membrane.core.interceptor.llmgateway;
 
 import com.predic8.membrane.core.exchange.Exchange;

core/src/main/java/com/predic8/membrane/core/interceptor/llmgateway/Policies.java

@@ -1,3 +1,17 @@
+/* Copyright 2026 predic8 GmbH, www.predic8.com
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
 package com.predic8.membrane.core.interceptor.llmgateway;
 
 import com.predic8.membrane.core.exchange.Exchange;

core/src/main/java/com/predic8/membrane/core/interceptor/llmgateway/SystemPrompt.java

@@ -1,3 +1,17 @@
+/* Copyright 2026 predic8 GmbH, www.predic8.com
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
 package com.predic8.membrane.core.interceptor.llmgateway;
 
 import com.predic8.membrane.annot.MCAttribute;

core/src/main/java/com/predic8/membrane/core/util/text/SerializationUtil.java

@@ -20,6 +20,7 @@
 
 import static com.predic8.membrane.core.http.MimeType.*;
 import static com.predic8.membrane.core.util.text.SerializationFunction.*;
+import static com.predic8.membrane.core.util.text.ToTextSerializer.toText;
 import static java.lang.Character.*;
 import static java.nio.charset.StandardCharsets.*;
 
@@ -150,7 +151,7 @@ public static String pathEncode(Object value) {
     public static String headerValueEncode(Object value) {
         if (value == null) return "";
 
-        String s = value.toString();
+        String s = toText(value);
         var out = new StringBuilder(s.length());
 
         for (int i = 0; i < s.length(); i++) {
@@ -165,4 +166,4 @@ public static String headerValueEncode(Object value) {
 
         return out.toString();
     }
-}
+}

core/src/test/java/com/predic8/membrane/core/interceptor/llmgateway/provider/AbstractLLMRequestTest.java

@@ -1,3 +1,17 @@
+/* Copyright 2026 predic8 GmbH, www.predic8.com
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
 package com.predic8.membrane.core.interceptor.llmgateway.provider;
 
 import com.predic8.membrane.core.exchange.Exchange;

core/src/test/java/com/predic8/membrane/core/lang/ScriptingUtilsTest.java

@@ -1,3 +1,17 @@
+/* Copyright 2026 predic8 GmbH, www.predic8.com
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
 package com.predic8.membrane.core.lang;
 
 import com.predic8.membrane.core.router.DefaultRouter;