code: def set_projection(self, val):
          
          knownproj = ["SIN", "ZEA", "TAN", "NCP", "AIT", "ZEA"]  # etc
          assert val.upper() in knownproj
          self._coord["projection"] = val.upper()
docs: Set the projection of the given axis in this coordinate.
  
          The known projections are SIN, ZEA, TAN, NCP, AIT, ZEA