// Gets all unique protocols from each chart series to ensure each protocol is only counted once
        private HashSet <Protocol> getUniqueProtocols(ChartSeries cs, HashSet <Protocol> protocolsUnique)
        {
            List <PatientProtocol> patientProtocols;
            List <Patient>         patients = cs.getPatients();

            foreach (Patient patient in patients)
            {
                patientProtocols = database.getPatientProtocol(patient);
                patientProtocols.ForEach(pp => protocolsUnique.Add(pp.Protocol));
            }
            return(protocolsUnique);
        }
 public DateTime getIntervalStartDate(Protocol protocol, Interval interval)
 {
     return(database.getPatientProtocol(this).FirstOrDefault(pp => pp.ProtocolID == protocol.Id).Start_Date);
 }