def _validate_use(use: str):
    """Validates the 'use' argument. If invalid, raises an error"""
    use = use.lower()
    valid_use_keywords = {'everything', 'pairwise.complete', 'complete'}
    if use not in valid_use_keywords:
        raise ValueError(f"use must be one of {', '.join(valid_use_keywords)}")
    return use
