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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_pageitems(_, token):
 """Show page items. Usage: .. code-block:: html+django {% show_pageitems per_page %} """

    # Validate args.
    if len(token.contents.split()) != 1:
        msg = '%r tag takes no arguments' % token.contents.split()[0]
        raise template.TemplateSyntaxError(msg)
    # Call the node.
    return ShowPageItemsNode()