OZG-4717 Verify isProduction is called

src/test/java/de/ozgcloud/admin/environment/FrontendEnvironmentControllerTest.java

@@ -53,6 +53,16 @@ class FrontendEnvironmentControllerTest {
 		@Nested
 		class TestBody {
 
+			@Test
+			@SneakyThrows
+			void shouldCallIsProduction() {
+				when(environmentProperties.isProduction()).thenReturn(true);
+
+				doRequest();
+
+				verify(environmentProperties).isProduction();
+			}
+
 			@ParameterizedTest
 			@ValueSource(booleans = { true, false })
 			@SneakyThrows