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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 rotate(self, azimuth, axis=None):
 """Rotate the trackball about the "Up" axis by azimuth radians. Parameters azimuth : float The number of radians to rotate. """

        target = self._target

        y_axis = self._n_pose[:3, 1].flatten()
        if axis is not None:
            y_axis = axis
        x_rot_mat = transformations.rotation_matrix(azimuth, y_axis, target)
        self._n_pose = x_rot_mat.dot(self._n_pose)

        y_axis = self._pose[:3, 1].flatten()
        if axis is not None:
            y_axis = axis
        x_rot_mat = transformations.rotation_matrix(azimuth, y_axis, target)
        self._pose = x_rot_mat.dot(self._pose)