我对plugin.go中的方法有疑问，发现here在Hyperledger结构库中。//Endorsesignsthegivenpayload(ProposalResponsePayloadbytes),andoptionallymutatesit.//Returns://TheEndorsement:Asignatureoverthepayload,andanidentitythatisusedtoverifythesignature//Thepayloadthatwasgivenasinput(couldbemodifiedwithinthisfunction)//Orerroro