This endpoint is to create an unsigned unbond transaction that can be broadcast to start the unstaking process of POL tokens from the Twinstake validator to the delegator's account. This is part 1 of a 2 stage process and the /unbond_claim endpoint mut be called next to complete the unstaking activity. This transaction must be broadcast on the Ethereum blockchain. For further information on the delegation and undelegation process please read the protocol's staking guide.