code: @Override
      public void visit(NodeVisitor v) {
          if (v.visit(this)) {
              varName.visit(v);
              if (catchCondition != null) {
                  catchCondition.visit(v);
              }
              body.visit(v);
          }
      }
docs: Visits this node, the catch var name node, the condition if
  non-{@code null}, and the catch body.