Services\Patient::toFhirValues PHP Method

    public function toFhirValues()
    {
        $values = parent::toFhirValues();
        if (!in_array($values['gender'], array(null, 'F', 'M'))) {
            $values['gender'] = 'UN';
        }
        $values['care_providers'] = array_filter(array_merge(array($values['gp_ref'], $values['prac_ref']), $values['cb_refs']));
        return $values;
    }