stake ctxt ~sender ~delegate amount add amount as sender's stake to delegate.

request_unstake ctxt ~sender_contract ~delegate amount records a request from sender_contract to unstake amount from delegate.

finalize_unstake ctxt contract performs the finalization of all unstake requests from contract that can be finalized. An unstake request can be finalized if it is old enough, specifically the requested amount must not be at stake anymore and must not be slashable anymore, i.e. after preserved_cycles + max_slashing_period after the request. Amounts are transferred from the contract's delegate (at request time) unstaked frozen deposits to contract's spendable balance, minus slashing the requested stake undergone in between.

punish_delegate ctxt delegate level mistake ~rewarded slashes delegate for a mistake at level and rewards rewarded.