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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 to_numpy(self):
 """ Converts this SFrame to a numpy array This operation will construct a numpy array in memory. Care must be taken when size of the returned object is big. Returns ------- out : numpy.ndarray A Numpy Array containing all the values of the SFrame """

        assert HAS_NUMPY, 'numpy is not installed.'
        import numpy
        return numpy.transpose(numpy.asarray([self[x] for x in self.column_names()]))