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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 merge_files(sources, destination):
 """Copy content of multiple files into a single file. :param list(str) sources: source file names (paths) :param str destination: destination file name (path) :return: """


    with open(destination, 'w') as hout:
        for f in sources:
            if os.path.exists(f):
                with open(f) as hin:
                    shutil.copyfileobj(hin, hout)
            else:
                logger.warning('File is missing: {}'.format(f))