add function

lib/base/code_editor/FileEditor.dart

@@ -0,0 +1,18 @@
+/// A file in the editor, used by EditorModel [model.code].
+///
+/// * [name] is the name of the file shown in the navbar.
+/// * [language] is the language used by the theme
+/// * [code] is the content of the file, the code
+///
+/// Tip: to simplify writing code in a String,
+/// write line by line your code in a list List<String> and pass as argument list.join("\n").
+class FileEditor {
+  late String name;
+  String? language;
+  String? code;
+  FileEditor({String? name, String? language, String? code}) {
+    this.name = name ?? "file.${language ?? 'txt'}";
+    this.language = language ?? "text";
+    this.code = code ?? "";
+  }
+}