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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 _update_cg(self):
 """Update the conjugate gradient"""

        beta = self._beta()
        # Automatic direction reset
        if beta < 0:
            self.direction = -self.gradient
            self.status = "SD"
        else:
            self.direction = self.direction * beta - self.gradient
            self.status = "CG"