code: func NewStructure(reader kv.Retriever, readWriter kv.RetrieverMutator, prefix []byte) *TxStructure {
  	return &TxStructure{
  		reader:     reader,
  		readWriter: readWriter,
  		prefix:     prefix,
  	}
  }
docs: // NewStructure creates a TxStructure with Retriever, RetrieverMutator and key prefix.