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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:

async def close(self, *, force_after=30):
        '''Close the connection and return when closed.'''
        if self.transport:
            self.transport.close()
            try:
                async with timeout_after(force_after):
                    await self.closed_event.wait()
            except TaskTimeout:
                self.abort()
                await self.closed_event.wait()