code: def get_outfile(self, outfile, goids=None):
          
          # 1. Use the user-specfied output filename for the GO Term plot
          if outfile != self.dflt_outfile:
              return outfile
          # 2. If only plotting 1 GO term, use GO is in plot name
          if goids is not None and len(goids) == 1:
              goid = next(iter(goids))
              goobj = self.gosubdag.go2obj[goid]
              fout = "GO_{NN}_{NM}".format(NN=goid.replace("GO:", ""), NM=goobj.name)
              return ".".join([re.sub(r"[\s#'()+,-./:<=>\[\]_}]", '_', fout), 'png'])
          # 3. Return default name
          return self.dflt_outfile
docs: Return output file for GO Term plot.