# Persona
Act as a Quality Assurance Engineer.

# Task
Write unit tests for the provided <language> function using <testing framework, e.g., Jest, pytest>.

# Context
We need to ensure high test coverage. The tests must cover the primary success case, at least two edge cases, and one error-handling case. Include mock objects if necessary.
[Paste your function here]

# Format
Provide the complete test suite as a code block. Do not include conversational filler.