/**
  * @return String containing names of all doctors in ascending order or "There are no doctors in
  *     the Council" String, if no doctors
  */
 public String allDoctors() {
   if (doctors.size() == 0) {
     return "There are no doctors in the Council";
   } else {
     String doctorsNames = "\n";
     sortDoctors();
     doctorsNames += "Doctors in the council:\n";
     for (Doctor doctor : doctors) {
       doctorsNames += "\t" + doctor.getName() + "\n";
     }
     return doctorsNames;
   }
 }
 public Billing(Doctor theDoctor, Patient thePatient) {
   aDoctor = theDoctor.getName();
   aPatient = thePatient.getName();
   billingAmount = theDoctor.getOfficeFee();
 }