Error: Could not resolve the package 'flutter_spinkit' in 'package:flutter_spinkit/flutter_spinkit.dart'

Compiler message: Error: Could not resolve the package 'flutter_spinkit' in 'package:flutter_spinkit/flutter_spinkit.dart'. lib/screens/authenticate/sign_in.dart:8:8: Error: Not found: 'package:flutter_spinkit/flutter_spinkit.dart' import 'package:flutter_spinkit/flutter_spinkit.dart';
       ^ lib/shared/loading.dart:2:8: Error: Not found: 'package:flutter_spinkit/flutter_spinkit.dart' import 'package:flutter_spinkit/flutter_spinkit.dart';
       ^ lib/shared/loading.dart:11:16: Error: The method 'SpinKitChasingDots' isn't defined for the class 'Loading'.
 - 'Loading' is from 'package:firebasestarter/shared/loading.dart' ('lib/shared/loading.dart'). Try correcting the name to the name of an existing method, or defining a method named 'SpinKitChasingDots'.
        child: SpinKitChasingDots(
               ^^^^^^^^^^^^^^^^^^

    import 'package:flutter/material.dart';
import 'package:flutter_spinkit/flutter_spinkit.dart';


class Loading extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      color:Colors.brown[400],
      child: Center(
        child: SpinKitChasingDots(
          color: Colors.brown,
          size: 50,
        ),
      ),
    );
  }
}