'Sets value of children count input'

@count.setter
def count(self, count):

    count_text = self.get_setting_element(self.COUNT_LABEL)
    count_text.send_keys(Keys.CONTROL, 'a')
    count_text.send_keys(Keys.BACK_SPACE)
    count_text.send_keys(count)
    EmptyPromise((lambda : (self.count == count)), 'count    is    updated    in    modal.').fulfill()
