def METHOD_NAME(filing_data: dict):
    user_id = filing_data.get('u_user_id')
    if user_id:
        first_name = filing_data.get('u_first_name')
        middle_name = filing_data.get('u_middle_name')
        last_name = filing_data.get('u_last_name')
        if first_name or middle_name or last_name:
            names = [first_name, middle_name, last_name]
            result = ' '.join([n for n in names if n])
            return result
        return user_id
    return ''