def is_expanded(request, key):
    """ Examines request object to return boolean of whether 
        passed field is expanded. 
    """
    expand = request.query_params.get('expand', '')
    expand_fields = []

    for e in expand.split(','):
        expand_fields.extend([e for e in e.split('.')]) 
        
    return '~all' in expand_fields or key in expand_fields