code: def _init_usrgos(self, goids):
          
          usrgos = set()
          goids_missing = set()
          _go2obj = self.gosubdag.go2obj
          for goid in goids:
              if goid in _go2obj:
                  usrgos.add(goid)
              else:
                  goids_missing.add(goid)
          if goids_missing:
              print("MISSING GO IDs: {GOs}".format(GOs=goids_missing))
              print("{N} of {M} GO IDs ARE MISSING".format(N=len(goids_missing), M=len(goids)))
          return usrgos
docs: Return user GO IDs which have GO Terms.