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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 is_version(value):
 """Validate that value is a valid version string."""

    try:
        value = str(value)
        if not parse_ver('1.4') <= parse_ver(value):
            raise ValueError()
        return value
    except (AttributeError, TypeError, ValueError):
        raise vol.Invalid(
            '{} is not a valid version specifier'.format(value))