def METHOD_NAME(self, collection_candidate):
    # type: (Candidate) -> dict[str, str]
    # FIXME: return Requirement instances instead?
    """Retrieve collection dependencies of a given candidate."""
    if collection_candidate.is_concrete_artifact:
        return (
            self.
            _concrete_art_mgr.
            get_direct_collection_dependencies
        )(collection_candidate)
    return (
        self.
        get_collection_version_metadata(collection_candidate).
        dependencies
    )