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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 do_placeholder(parser, token):
 """ Method that parse the placeholder template tag. Syntax:: {% placeholder <name> [on <page>] [with <widget>] \ [parsed] [as <varname>] %} Example usage:: {% placeholder about %} {% placeholder body with TextArea as body_text %} {% placeholder welcome with TextArea parsed as welcome_text %} {% placeholder teaser on next_page with TextArea parsed %} """

    name, params = parse_placeholder(parser, token)

    return PlaceholderNode(name, **params)