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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 upgrade(cfg):
 """Provide forward migration for configuration files."""

    db_node = cfg["db"]
    old_db_elems = ["host", "name", "port", "pass", "user", "dialect"]
    has_old_db_elems = [x in db_node for x in old_db_elems]

    if any(has_old_db_elems):
        print("Old database configuration found. "
              "Converting to new connect_string. "
              "This will *not* be stored in the configuration automatically.")
        cfg["db"]["connect_string"] = \
            "{dialect}://{user}:{password}@{host}:{port}/{name}".format(
                dialect=cfg["db"]["dialect"]["value"],
                user=cfg["db"]["user"]["value"],
                password=cfg["db"]["pass"]["value"],
                host=cfg["db"]["host"]["value"],
                port=cfg["db"]["port"]["value"],
                name=cfg["db"]["name"]["value"])