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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 generate_report(book_url):
 # commodity: CommodityOption( # section="Commodity", # sort_tag="a", # documentation_string="This is a stock", # default_value="VTIP"), # commodity_list: CommodityListOption( # section="Commodity", # sort_tag="a", # documentation_string="This is a stock", # default_value="VTIP") #):
 """ Generates an HTML report content. """

    # Report variables
    shares_no = None
    avg_price = None

    stock_template = templates.load_jinja_template("stock_template.html")
    stock_rows = ""

    with piecash.open_book(book_url, readonly=True, open_if_lock=True) as book:
        # get all commodities that are not currencies.
        all_stocks = portfoliovalue.get_all_stocks(book)
        for stock in all_stocks:
            for_date = datetime.today().date
            model = portfoliovalue.get_stock_model_from(book, stock, for_date)
            stock_rows += stock_template.render(model)

    # Load HTML template file.
    template = templates.load_jinja_template("template.html")
    # Render the full report.
    #return template.format(**locals())
    result = template.render(**locals())
    return result