// whether the value indicated by the key exists in the trie that generates the proofchain
whether the value indicated by the key exists in the trie that generates the proofchain
// whether the value indicated by the key exists in the trie that generates the proofchain
func (c ProofChain) IsExist(key []byte) (bool, error) {
	if len(key) == 0 {
		return false, common.ErrNil
	}
	prefix := keyToPrefix(key)
	h, err := c.Exist(prefix)
	if err != nil {
		return false, err
	}
	return h != nil, nil
}
func ( c ProofChain ) IsExist ( key [ ] byte ) ( bool , error ) { if len ( key ) == 0 { return false , common . ErrNil } prefix := keyToPrefix ( key ) h , err := c . Exist ( prefix ) if err != nil { return false , err } return h != nil , nil }
whether the value indicated by the key exists in the trie that generates the proofchain
whether the value indicated by the key exists in the trie that generates the proofchain