main.dart

class Test {
  bool? a;
  bool? b;
  String? ex;
  String? yz;

  Test({
    this.a,
    this.b,
    this.ex,
    this.yz,
  });

   Map<String, dynamic> toJson() =>
      {
        "a": a,
        "b": b,
        "ex": ex,
        "yz": yz,

      };

  Test copy({bool? a, bool? b, String? ex, String? yz}){
    return Test(
      a : a ?? this.a,
      b : b ?? this.b,
      ex : ex ?? this.ex,
      yz : yz ?? this.yz,
    );
  }


}

void main() {
  Test a = Test(
    a : true,
    b : false,
    ex : "S001",
    yz : "plus"
  );

  Test b = Test(
    a : false,
    b : true,
    ex : "S001",
    yz : "plus"
  );

  Test c = Test(
    a : true,
    b : true,
    ex : "S001",
    yz : "plus"
  );

  Test d = Test(
    a : false,
    b : false,
    ex : "S001",
    yz : "plus"
  );

  Test z = a.copy(); // we want to remove an object with attributes matching 'a' from the list

  List<Test> testList = [a, b, c, d];

  for(var item in testList){ print(item.toJson()); } // [a, b, c, d]

  var result = testList.remove(a.copy());

  print(result);

  for(var item in testList){ print(item.toJson()); }

}