code: def _visit_shape_te(self, te: ShExJ.tripleExpr, visit_center: _VisitorCenter) -> None:
          
          if isinstance(te, ShExJ.TripleConstraint) and te.valueExpr is not None:
              visit_center.f(visit_center.arg_cntxt, te.valueExpr, self)
docs: Visit a triple expression that was reached through a shape. This, in turn, is used to visit additional shapes
          that are referenced by a TripleConstraint
          :param te: Triple expression reached through a Shape.expression
          :param visit_center: context used in shape visitor