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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 create_package_version(requirement):
 """Create a new PackageVersion from a requirement. Handles errors."""

    try:
        PackageVersion(requirement=requirement).save()
        logger.info("Package '%s' added.", requirement.name)  # noqa
    except IntegrityError:
        logger.info("Package '%s' already exists.", requirement.name)