def METHOD_NAME(gitlab_variables):
    # pop properties we don't know
    existing_variables = [dict(x.attributes) for x in gitlab_variables]
    KNOWN = ['key', 'value', 'masked', 'protected', 'variable_type', 'environment_scope']
    for item in existing_variables:
        for key in list(item.keys()):
            if key not in KNOWN:
                item.pop(key)
    return existing_variables