code: def fix_normals(self, multibody=None):
          
          if multibody is None:
              multibody = self.body_count > 1
          repair.fix_normals(self, multibody=multibody)
docs: Find and fix problems with self.face_normals and self.faces
          winding direction.
  
          For face normals ensure that vectors are consistently pointed
          outwards, and that self.faces is wound in the correct direction
          for all connected components.
  
          Parameters
          -------------
          multibody : None or bool
            Fix normals across multiple bodies
            if None automatically pick from body_count