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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 _get_baseline_string_from_file(filename):
 # pragma: no cover """Breaking this function up for mockability."""

    try:
        with open(filename) as f:
            return f.read()

    except IOError:
        log.error(
            'Unable to open baseline file: {}\n'
            'Please create it via\n'
            '   `detect-secrets scan > {}`\n'
            .format(filename, filename),
        )
        raise