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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 tar_to_bigfile(self, fname, outfile):
 """Convert tar of multiple FASTAs to one file."""

        fnames = []
        tmpdir = mkdtemp()
        
        # Extract files to temporary directory
        with tarfile.open(fname) as tar:
            tar.extractall(path=tmpdir)
        for root, _, files in os.walk(tmpdir):
            fnames += [os.path.join(root, fname) for fname in files]
        
        # Concatenate
        with open(outfile, "w") as out:
            for infile in fnames:
                for line in open(infile):
                    out.write(line)
                os.unlink(infile)
        
        # Remove temp dir
        shutil.rmtree(tmpdir)