Action: Undelegate

The controllable parameters of the Undelegate action are

• the validator_identity — this is how the validator to undelegate from is identified

• the start_epoch_index — is the epoch the delegation started, it is used for verification

• the unbonded_amount — the expected unbonded amount

• the delegation_amount — the amount to undelegate

For this action handler, there is no check_stateless check.

The check_stateful check ensures that the validator exists, that the epoch is correct by comparing it to the validator's next rate data, and that the parameters match. It then verifies that the returned delegation_amount matches the expected unbonded_amount.

The execute registers the undelegation for execution at the end of the block and registers an undelegation denominator.