docs: def _get_drive_type_and_speed(self):
          """Gets the disk drive type.
  
          :returns: A dictionary with the following keys:
              - has_rotational: True/False. It is True if atleast one
              rotational disk is attached.
              - has_ssd: True/False. It is True if at least one SSD disk is
              attached.
              - drive_rotational_<speed>_rpm: These are set to true as
                per the speed of the rotational disks.
          :raises: IloCommandNotSupportedError if the PhysicalDrives resource
              doesn't exist.
          :raises: IloError, on an error from iLO.
          """
          disk_details = self._get_physical_drive_resource()
          drive_hdd = False
          drive_ssd = False
          drive_details = {}
          speed_const_list = [4800, 5400, 7200, 10000, 15000]
          if disk_details:
              for item in disk_details:
                  value = item['MediaType']
                  if value == "HDD":
                      drive_hdd = True
                      speed = item['RotationalSpeedRpm']
                      if speed in speed_const_list:
                          var = 'rotational_drive_' + str(speed) + '_rpm'
                          drive_details.update({var: 'true'})
                  # Note: RIS returns value as 'SDD' for SSD drives.
                  else:
                      drive_ssd = True
          if drive_hdd:
              drive_details.update({'has_rotational': 'true'})
          if drive_ssd:
              drive_details.update({'has_ssd': 'true'})
          return drive_details if len(drive_details.keys()) > 0 else None