def METHOD_NAME(self, N = 10):
    """Fill the bar in N frames. This call is blocking."""
    remaining = self['range'] - self['value']
    if remaining:
        step = max(1, int(remaining / N))
        count = self['value']
        while count != self['range']:
            count += step
            if count > self['range']:
                count = self['range']
            self.update(count)