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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 scipy_solve_symm_block_tridiag(H_diag, H_upper_diag, v, ab=None):
 """ use scipy.linalg.solve_banded to solve a symmetric block tridiagonal system see https://docs.scipy.org/doc/scipy/reference/generated/scipy.linalg.solveh_banded.html """

    from scipy.linalg import solveh_banded
    ab = convert_block_tridiag_to_banded(H_diag, H_upper_diag) \
        if ab is None else ab
    x = solveh_banded(ab, v.ravel(), lower=True)
    return x.reshape(v.shape)