human
Complete the below
def _encode(obj, namespace_public_id=None, expand=False, is_n1=False):

    ''''Returns a dictionary representation of a Nylas model object obj, or
    None if there is no such representation defined. If the optional
    namespace_public_id parameter is passed, it will used instead of fetching
    the namespace public id for each object. This improves performance when
    serializing large numbers of objects, but also means that you must take
    care to ONLY serialize objects that belong to the given namespace!
    Parameters
    namespace_public_id: string, optional
    public id of the namespace to which the object to serialize belongs.
    Returns
    dictionary or None'
    '''
assistant
#Here is the Python code you requested.
    def _get_namespace_public_id(obj):
        return (namespace_public_id or obj.namespace.public_id)
    def _format_participant_data(participant):
        'Event.participants    is    a    JSON    blob    which    may    contain    internal    data.\n                                This    function    returns    a    dict    with    only    the    data    we    want    to    make\n                                public.'
        dct = {}
        for attribute in ['name', 'status', 'email', 'comment']:
            dct[attribute] = participant.get(attribute)
        return dct
    def _get_lowercase_class_name(obj):
        return type(obj).__name__.lower()
    if isinstance(obj, datetime.datetime):
        return calendar.timegm(obj.utctimetuple())
    if isinstance(obj, datetime.date):
        return obj.isoformat()
    if isinstance(obj, arrow.arrow.Arrow):
        return encode(obj.datetime)
    if isinstance(obj, Namespace):
        acc_state = obj.account.sync_state
        if (acc_state is None):
            acc_state = 'running'
        if (is_n1 and (acc_state not in ['running', 'invalid'])):
            acc_state = 'running'
        resp = {'id': obj.public_id, 'object': 'account', 'account_id': obj.public_id, 'email_address': (obj.account.email_address if obj.account else ''), 'name': obj.account.name, 'provider': obj.account.provider, 'organization_unit': obj.account.category_type, 'sync_state': acc_state}
        if (expand and obj.account.server_settings):
            resp['server_settings'] = obj.account.server_settings
        return resp
    elif isinstance(obj, Account):
        raise Exception('Should    never    be    serializing    accounts')
    elif isinstance(obj, Message):
        thread_public_id = None
        if obj.thread:
            thread_public_id = obj.thread.public_id
        resp = {'id': obj.public_id, 'object': 'message', 'account_id': _get_namespace_public_id(obj), 'subject': obj.subject, 'from': format_address_list(obj.from_addr), 'reply_to':...