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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 get_jtimes(self):
 """ Derive the jacobian-vector product from ``self.exprs`` and ``self.dep``"""

        if self._jtimes is False:
            return False

        if self._jtimes is True:
            r = self.be.Dummy('r')
            v = tuple(self.be.Dummy('v_{0}'.format(i)) for i in range(self.ny))
            f = self.be.Matrix(1, self.ny, self.exprs)
            f = f.subs([(x_i, x_i + r * v_i) for x_i, v_i in zip(self.dep, v)])
            return v, self.be.flatten(f.diff(r).subs(r, 0))
        else:
            return tuple(zip(*self._jtimes))