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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 reset(self):
 """ Resets the connection pool back to a clean state. """

        self.pid = os.getpid()
        self._created_connections = 0
        self._created_connections_per_node = {}  # Dict(Node, Int)
        self._available_connections = {}  # Dict(Node, List)
        self._in_use_connections = {}  # Dict(Node, Set)
        self._check_lock = threading.Lock()
        self.initialized = False