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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 show_all_categories(call=None):
    '''
    Return a dict of all available categories on the cloud provider.

    .. versionadded:: 2016.3.0
    '''
    if call == 'action':
        raise SaltCloudSystemExit(
            'The show_all_categories function must be called with -f or --function.'
        )

    conn = get_conn(service='SoftLayer_Product_Package')
    categories = []

    for category in conn.getCategories(id=50):
        categories.append(category['categoryCode'])

    return {'category_codes': categories}