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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 _example_short_number(region_code):
 """Gets a valid short number for the specified region. Arguments: region_code -- the region for which an example short number is needed. Returns a valid short number for the specified region. Returns an empty string when the metadata does not contain such information. """

    metadata = PhoneMetadata.short_metadata_for_region(region_code)
    if metadata is None:
        return U_EMPTY_STRING
    desc = metadata.short_code
    if desc.example_number is not None:
        return desc.example_number
    return U_EMPTY_STRING