how to use unnamed costructer in flutter code example

Example 1: fluter class constructor

class Customer {
  String name;
  int age;
  String location;

  // constructor
  Customer(String name, int age, String location) {
    this.name = name;
    this.age = age;
    this.location = location;
  }
}

Example 2: constructoers in flutter

Customer(this.name, this.age, this.location);

Customer.withoutLocation(this.name, this.age);

Customer.empty() {
  name = "";gd
  location = "";
}
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