code: @TargetApi(Build.VERSION_CODES.GINGERBREAD)
      public void apply() {
          if (editing == null) {
              return;
          }
          try {
              editing.apply();
          } catch (Exception ex) {
              editing.commit(); // Fallback in case low api lever.
          }
          editing = null;
      }
docs: Call to apply changes.
  @see android.content.SharedPreferences.Editor#apply()