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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 are_checksums_equal(checksum_a_pyxb, checksum_b_pyxb):
 """Determine if checksums are equal. Args: checksum_a_pyxb, checksum_b_pyxb: PyXB Checksum objects to compare. Returns: bool - **True**: The checksums contain the same hexadecimal values calculated with the same algorithm. Identical checksums guarantee (for all practical purposes) that the checksums were calculated from the same sequence of bytes. - **False**: The checksums were calculated with the same algorithm but the hexadecimal values are different. Raises: ValueError The checksums were calculated with different algorithms, hence cannot be compared. """

    if checksum_a_pyxb.algorithm != checksum_b_pyxb.algorithm:
        raise ValueError(
            'Cannot compare checksums calculated with different algorithms. '
            'a="{}" b="{}"'.format(checksum_a_pyxb.algorithm, checksum_b_pyxb.algorithm)
        )
    return checksum_a_pyxb.value().lower() == checksum_b_pyxb.value().lower()