Answer:
Java class is given below
Step-by-step explanation:
public abstract class Phone
{private
String phoneNumber;
public Phone(String phoneNumber)
{
this.phoneNumber = phoneNumber;
}
public String getPhoneNumber()
{
return this.phoneNumber;
}
public String toString()
{
return "#("+this.phoneNumber+")";
}
public abstract boolean createConnection(Network n);
public abstract void closeConnection();
}