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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 diff_values(value_a, value_b, raw=False):
 """Returns a human-readable diff between two values :param value_a: First value to compare :param value_b: Second value to compare :param raw: True to compare the raw values, e.g. UIDs :returns a list of diff tuples """


    if not raw:
        value_a = _process_value(value_a)
        value_b = _process_value(value_b)

    # No changes
    if value_a == value_b:
        return None

    diffs = []
    # N.B.: the choice for the tuple data structure is to enable in the future
    # more granular diffs, e.g. the changed values within a dictionary etc.
    diffs.append((value_a, value_b))
    return diffs