code: def add_pos_indicator(self):
          
          body = new_body(name="pos_indicator")
          body.append(
              new_geom(
                  "sphere",
                  [0.03],
                  rgba=[1, 0, 0, 0.5],
                  group=1,
                  contype="0",
                  conaffinity="0",
              )
          )
          body.append(new_joint(type="free", name="pos_indicator"))
          self.worldbody.append(body)
docs: Adds a new position indicator.