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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 __builder_connect_pending_signals(self):
 """Called internally to actually make the internal Gtk.Builder instance connect all signals found in controllers controlling self."""

        class _MultiHandlersProxy (object):
            def __init__(self, funcs): self.funcs = funcs
            def __call__(self, *args, **kwargs):
                # according to gtk documentation, the return value of
                # a signal is the return value of the last executed
                # handler
                for func in self.funcs:
                    res = func(*args, **kwargs)
                return res

        final_dict = {n: (v.pop() if len(v) == 1
                          else _MultiHandlersProxy(v))
                      for n, v in self.builder_pending_callbacks.items()}

        self._builder.connect_signals(final_dict)

        self.builder_connected = True
        self.builder_pending_callbacks = {}