Update dict with fields from obj.attributes.

    :param obj: the object updated into dict
    :param dict: the result dictionary
    :param attributes: a list of attributes belonging to obj

def update_dict(obj, dict, attributes):
    """Update dict with fields from obj.attributes.

    :param obj: the object updated into dict
    :param dict: the result dictionary
    :param attributes: a list of attributes belonging to obj
    """
    for attribute in attributes:
        if hasattr(obj, attribute) and getattr(obj, attribute) is not None:
            dict[attribute] = getattr(obj, attribute)