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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 get_first_builder_window(builder):
 """Get the first toplevel widget in a Gtk.Builder hierarchy. This is mostly used for guessing purposes, and an explicit naming is always going to be a better situation. """

    for obj in builder.get_objects():
        if isinstance(obj, Gtk.Window):
            # first window
            return obj