Implement a hierarchical key-value store

Implement an in-memory hierarchical key-value store where keys are UNIX-like paths joined by '/'. The root node is '/' with initial value '#'. Each node stores a string value. Support: ( 1) Create(path, value): create a node; parent must exist; fail if the node already exists. ( 2) SetValue(path, value): set the value; node must exist. ( 3) GetValue(path): return the value; node must exist. ( 4) Delete(path): delete the node only if it has no children; node must exist. Define the class interface, choose appropriate data structures, and provide time/space complexities. Include unit tests and discuss how you would add concurrency safety and optional persistence to disk.