Refactor input resource setup in FieldTest

This commit enhances readability by restructuring how the input resource 'Example' class is added in the 'testArrayLengthDeclaringTypeNested' method within FieldTest. The addition process is now within a single method call to 'addInputResource', improving code clarity and maintainability without altering functionality.

src/test/java/spoon/test/field/FieldTest.java

@@ -277,13 +277,15 @@ void testArrayLengthModifiers() {
 	void testArrayLengthDeclaringTypeNested() {
 		// contract: the declaring type of a "length" access on arrays is set even when nested
 		Launcher launcher = new Launcher();
-		launcher.addInputResource(new VirtualFile("public class Example {\n" +
-																							"	public String[] array = new String[4];\n" +
-																							"	public static void main(String[] args) {\n" +
-																							"		Example other = new Example();\n" +
-																							"		int i = other.array.length;\n" +
-																							"	}\n" +
-																							"}"));
+		launcher.addInputResource(new VirtualFile(
+						"public class Example {\n" +
+						"	public String[] array = new String[4];\n" +
+						"	public static void main(String[] args) {\n" +
+						"		Example other = new Example();\n" +
+						"		int i = other.array.length;\n" +
+						"	}\n" +
+						"}"
+		));
 
 		CtModel ctModel = launcher.buildModel();
 		List<CtFieldReference<?>> elements = ctModel.getElements(new TypeFilter<>(CtFieldReference.class));