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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def itransform(self, seq):
 """Transform a sequence of points or vectors in place. :param seq: Mutable sequence of :class:`~planar.Vec2` to be transformed. :returns: None, the input sequence is mutated in place. """

        if self is not identity and self != identity:
            sa, sb, sc, sd, se, sf, _, _, _ = self
            for i, (x, y) in enumerate(seq):
                seq[i] = (x * sa + y * sd + sc, x * sb + y * se + sf)