human
What is a the Python program you requested given the following:
Complete the below
def initialize_decorator(init):

    ''''Ensure that the length of string field do not exceed the limit.
    This decorator check the initialize arguments, to make sure the
    length of string field do not exceed the length limit, or raise a
    \'StringLengthExceeded\' exception.
    Use decorator instead of inheritance, because the metaclass will
    check the __tablename__, primary key columns, etc. at the class
    definition.'
    '''
assistant
#Here is the Python program you requested.
    def initialize(self, *args, **kwargs):
        cls = type(self)
        for (k, v) in kwargs.items():
            if hasattr(cls, k):
                attr = getattr(cls, k)
                if isinstance(attr, InstrumentedAttribute):
                    column = attr.property.columns[0]
                    if isinstance(column.type, String):
                        if (column.type.length and (column.type.length < len(str(v)))):
                            if ((config.CONF.signing.token_format == 'PKI') and (self.__tablename__ == 'token') and (k == 'id')):
                                continue
                            raise exception.StringLengthExceeded(string=v, type=k, length=column.type.length)
        init(self, *args, **kwargs)
    return initialize