NewClient returns a wrapped etcd client.

NewClientFromCfg returns a wrapped etcd client.

CreateOp is create operation type.

DeleteOp is delete operation type.

UpdateOp is update operation type.

Client is a wrapped etcd client that support some simple method.

Node organizes the ectd query result as a Trie tree.

Operation represents an operation in etcd, include create, update and delete.

OpType is operation's type in etcd.