diff --git a/src/common/I18n.js b/src/common/I18n.js
index 8d80a8510bc5c..a2eccc08ac054 100644
--- a/src/common/I18n.js
+++ b/src/common/I18n.js
@@ -2,12 +2,25 @@
  * I18n translation class.
  */
 class I18n {
+  /**
+   * Constructor.
+   *
+   * @param {Object} options Options.
+   * @param {string} options.locale Locale.
+   * @param {Object} options.translations Translations.
+   */
   constructor({ locale, translations }) {
     this.locale = locale;
     this.translations = translations;
     this.fallbackLocale = "en";
   }
 
+  /**
+   * Get translation.
+   *
+   * @param {string} str String to translate.
+   * @returns {string} Translated string.
+   */
   t(str) {
     const locale = this.locale || this.fallbackLocale;