docs: def get_physical_drive_by_id(self, id):
          """Get a PhysicalDrive object for given id.
  
          This method examines both assigned and unassigned physical
          drives of the controller and returns the physical drive.
  
          :param id: id of physical drive, for example '5I:1:1'.
          :returns: PhysicalDrive object having the id, or None if
              physical drive is not found.
          """
          for phy_drive in self.unassigned_physical_drives:
              if phy_drive.id == id:
                  return phy_drive
          for array in self.raid_arrays:
              for phy_drive in array.physical_drives:
                  if phy_drive.id == id:
                      return phy_drive
          return None