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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 init(self, key, value):
 """ Initializes a single or a sequence of key-value pairs into the store. For each key, one must `init` it before calling `push` or `pull`. When multiple workers invoke `init` for the same key, only the value supplied by worker with rank `0` is used. This function returns after data has been initialized successfully. Parameters key : str, int, or sequence of str or int The keys. value : NDArray, RowSparseNDArray or sequence of NDArray or RowSparseNDArray Values corresponding to the keys. Examples -------- [[ 2. 2. 2.] [ 2. 2. 2.]] <RowSparseNDArray 2x3 @cpu(0)> """

        ckeys, cvals, use_str_keys = _ctype_key_value(key, value)
        if use_str_keys:
            check_call(_LIB.MXKVStoreInitEx(self.handle, mx_uint(len(ckeys)), ckeys, cvals))
        else:
            check_call(_LIB.MXKVStoreInit(self.handle, mx_uint(len(ckeys)), ckeys, cvals))