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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 decompress_array(str_list):
 """ Decompress a list of strings """

    global _compress_thread_pool

    if not str_list:
        return str_list

    if not ENABLE_PARALLEL or len(str_list) <= LZ4_N_PARALLEL:
        return [lz4_decompress(chunk) for chunk in str_list]

    if _compress_thread_pool is None:
        _compress_thread_pool = ThreadPool(LZ4_WORKERS)
    return _compress_thread_pool.map(lz4_decompress, str_list)