code: private static NameSpace getEngineNameSpace(ScriptContext scriptContext) {
          Map<String, Object> engineView = new ScriptContextEngineView(scriptContext);
          NameSpace ns = (NameSpace) engineView.get(engineNameSpaceKey);
  
          if (!engineView.containsKey(engineNameSpaceKey)) {
              // Create a global namespace for the interpreter
              ns = new ExternalNameSpace(null/*parent*/, "javax_script_context", engineView);
              engineView.put(engineNameSpaceKey, ns);
          }
  
          return ns;
      }
docs: /*
  Check the context for an existing global namespace embedded
  in the script context engine scope.  If none exists, ininitialize the
  context with one.