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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 prt_ver(self, prt):
 """Print version of GO-DAG for the GO and for GO slims."""

        if self.ver_list is not None:
            prt.write("# Versions:\n#    {VER}\n\n".format(VER="\n#    ".join(self.ver_list)))