def get_last_version(documents):
    """
    Helper function to get the last version of the list of documents provided.

    :param documents: List of documents to check.
    :type documents: [cla.models.model_interfaces.Document]
    :return: 2-item tuple containing (major, minor) version number.
    :rtype: tuple
    """
    last_major = 0  # 0 will be returned if no document was found.
    last_minor = -1  # -1 will be returned if no document was found.
    for document in documents:
        current_major = document.get_document_major_version()
        current_minor = document.get_document_minor_version()
        if current_major > last_major:
            last_major = current_major
            last_minor = current_minor
            continue
        if current_major == last_major and current_minor > last_minor:
            last_minor = current_minor
    return last_major, last_minor