'Represents arguments specified to :meth:`.Select.for_update`.
.. versionadded:: 0.9.0'

def __init__(self, nowait=False, read=False, of=None):

    self.nowait = nowait
    self.read = read
    if (of is not None):
        self.of = [_interpret_as_column_or_from(elem) for elem in util.to_list(of)]
    else:
        self.of = None
