void main() {
  doSmth(MongoDB());
}

void doSmth(DB db) {
  final success = db.create('Ahmed', 'name');
  if (success)
    print('Succeeded');
  else
    print('Failed');
}

enum EatingType { meat, plant, both }

abstract class DB {
  bool create(String value, String key);
  String read(String key);
  bool update(String newValue, String key);
  bool delete(String key);
}

class MongoDB implements DB {
  @override
  bool create(String value, String key) => false;

  @override
  bool delete(String key) => true;

  @override
  String read(String key) => 'Mohammed';

  @override
  bool update(String newValue, String key) => false;
}

class FirestoreDB implements DB {
  @override
  bool create(String value, String key) {
    //lsdjflk
    //lkjsdf
    //lkjadsf
    //lksjdf

    return true;
  }

  @override
  bool delete(String key) => false;

  @override
  String read(String key) => 'Ahmed';

  @override
  bool update(String newValue, String key) => true;
}

abstract class Animal {
  Animal(this.age, this.eatingType, this.legsCount);
  int age;
  final EatingType eatingType;
  final int legsCount;

  String speak();

  @override
  String toString() =>
      'Age: $age, Eating Type: $eatingType, Legs Count: $legsCount, and says: ${speak()}';
}

class Cat extends Animal {
  Cat(int age) : super(age, EatingType.meat, 4);

  @override
  String speak() => 'Meoow';

  String play() => 'Playing smth';
}

class Cow extends Animal {
  Cow(int age) : super(age, EatingType.plant, 4);

  @override
  String speak() => 'Mooo';
}
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