| Elektra 0.11.0

Use Case: `Key` Value

# Summary

- Scope: `libelektra-core`
- Level: Developer Goal
- Actors: Core, Caller
- Brief: Access to and manipulation of `Key`'s value

# Scenarios

- Precondition:
  - `Key` has been created
- Main success scenario:
  - Caller requests current value of `Key`
  - Core returns current value of `Key`
- Alternative scenario:
  - Caller requests to change value of `Key` to new value
  - Core stores new value in `Key`
- Error scenario: -
- Postcondition: -
- Non-functional Constraints: -