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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 _make_suffix(cov):
 """Create a suffix for nbval data file depending on pytest-cov config."""

    # Check if coverage object has data_suffix:
    if cov and cov.data_suffix is not None:
        # If True, the suffix will be autogenerated by coverage.py.
        # The suffixed data files will be automatically combined later.
        if cov.data_suffix is True:
            return True
        # Has a suffix, but we add our own extension
        return cov.data_suffix + '.nbval'
    return 'nbval'