put the line "import polymake" before "polymake.cube(15)"

Author: cxzhong

src/sage/interfaces/polymake.py

@@ -446,8 +446,8 @@ def clear(self, var):
         TESTS::
 
             sage: # optional - jupymake
-            sage: c = polymake.cube(15)
             sage: from sage.interfaces.polymake import polymake
+            sage: c = polymake.cube(15)
             sage: polymake._available_vars = []
             sage: old = c._name
             sage: del c