$(30$ points $)$ A database system used by a hospital to record information about patients and wards has the following relations: Wards$($number$,$ numBeds$)$ Patients $($pid$,$ name, year, gender$)$ PatientInWard$($pid$,$ ward$)$ Tests$($patient$,$ testDate, test Hour, temperature, heart Rate$)$ A ward is identified by its number. Attribute numBeds is the number of beds in that ward. Patients are identified by their personal identification number. The name, year of birth and gender $(\text{'}$M$\text{'}$ or $\text{'}$ F $\text{'})$ of each patient is stored in the Patients relation. The ward to which each patient is assigned is stored in relation PatientInWard. During their stay in hospital, patients will undergo routine tests. The date and hour of each occasion when these tests are performed on a patient are recorded, and for each of these tests the patient's temperature and heart rate are measured and recorded in the database. A patient will normally undergo these routine tests several times during their stay in hospital. a$.(4$ pts$)$ Populate each relation with one sample tuple. b$.(12$ pts$)$ Draw the schema for the database system of hospital with complete specifications of primary keys, foreign keys and referential integrity constraints.