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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 vars_to_array(self):
 """ Convert `self.vars` to a numpy array Returns ------- numpy.array """


        logger.warn('This function is deprecated. You can inspect `self.np_vars` directly as NumPy arrays '
                    'without conversion.')
        if not self.vars:
            return None

        vars_matrix = matrix(self.vars, size=(self.vars[0].size[0],
                                              len(self.vars))).trans()

        self.vars_array = np.array(vars_matrix)

        return self.vars_array