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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 preShear(self, h, v):
 """Calculate pre shearing and replace current matrix."""

        a, b = self.a, self.b
        self.a += v * self.c
        self.b += v * self.d
        self.c += h * a
        self.d += h * b
        return self