Close resource in use.

def do_close(self, args):
        """Close resource in use."""

        if not self.current:
            print('There are no resources in use. Use the command "open".')
            return

        try:
            self.current.close()
        except Exception as e:
            print(e)
        else:
            print('The resource has been closed.')
            self.current = None
            self.prompt = self.default_prompt