when I use persistent_bottom_nav_bar package in my flutter app
this error is appearing
` Error: The getter ‘backgroundColor’ isn’t defined for the class ‘ThemeData’.

• ‘ThemeData’ is from ‘package:flutter/src/material/theme_data.dart’ (‘/C:/src/flutter/packages/flutter/lib/src/material/theme_data.dart’).
  Try correcting the name to the name of an existing getter, or defining a getter or field named ‘backgroundColor’.
  final color = decoration.color ?? Theme.of(context).backgroundColor;
  ^^^^^^^^^^^^^^^`

try to run my flutter app