GasCostSummary

Summary of charges from transactions.

Storage is charged in three parts -- storage_cost, -storage_rebate, and non_refundable_storage_fee -- independently of computation_cost.

The overall cost of a transaction, deducted from its gas coins, is its computation_cost + storage_cost - storage_rebate. non_refundable_storage_fee is collected from objects being mutated or deleted and accumulated by the system in storage funds, the remaining storage costs of previous object versions are what become the storage_rebate. The ratio between non_refundable_storage_fee and storage_rebate is set by the protocol.