public void test_evaluate_stringOperations() {
        final Map<String, Object> params = new HashMap<>();
        params.put("first", "Hello");
        params.put("second", "World");

        assertEquals("HelloWorld", groovyEngine.evaluate("return first + second", params));
        assertEquals("HELLO", groovyEngine.evaluate("return first.toUpperCase()", params));
        assertEquals(5, groovyEngine.evaluate("return first.length()", params));

 * directive:
 *
 * ```java
 * Request request = new Request.Builder()
 *     .cacheControl(new CacheControl.Builder().noCache().build())
 *     .url("http://publicobject.com/helloworld.txt")
 *     .build();
 * ```
 *
 * If it is only necessary to force a cached response to be validated by the server, use the more
 * efficient `max-age=0` directive instead:
 *
 * ```java

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client = OkHttpClient()

      fun run() {
        val request = Request.Builder()
            .url("https://publicobject.com/helloworld.txt")
            .build()

        client.newCall(request).execute().use { response ->
          if (!response.isSuccessful) throw IOException("Unexpected code $response")