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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 xrdb(xrdb_files=None):
 """Merge the colors into the X db so new terminals use them."""

    xrdb_files = xrdb_files or \
        [os.path.join(CACHE_DIR, "colors.Xresources")]

    if shutil.which("xrdb") and OS != "Darwin":
        for file in xrdb_files:
            subprocess.run(["xrdb", "-merge", "-quiet", file])