set_update_policy
Description:
Sets the policy for updating the spin row.
The options are always, or only when the value is invalid.
Parameters:
| this | a spin row | 
| policy | the policy for updating the spin row | 
Sets the policy for updating the spin row.
The options are always, or only when the value is invalid.
| this | a spin row | 
| policy | the policy for updating the spin row |