[khusamov]

Наследование от Ext.Ajax нельзя делать?
При попытке наследоваться возникает ошибка:

Uncaught TypeError: Cannot read property 'defaultConfig' of undefined
    at Function.<anonymous> (ext-all-rtl-debug.js?_dc=1485867203820:13398)
    at Function.doProcess (ext-all-rtl-debug.js?_dc=1485867203820:13236)
    at ext-all-rtl-debug.js?_dc=1485867203820:19882
    at Object.load (ext-all-rtl-debug.js?_dc=1485867203820:19390)
    at Object.require (ext-all-rtl-debug.js?_dc=1485867203820:19323)
    at Object.require (ext-all-rtl-debug.js?_dc=1485867203820:14165)
    at Function.<anonymous> (ext-all-rtl-debug.js?_dc=1485867203820:19856)
    at Function.doProcess (ext-all-rtl-debug.js?_dc=1485867203820:13236)
    at Function.process (ext-all-rtl-debug.js?_dc=1485867203820:13227)
    at new ExtClass (ext-all-rtl-debug.js?_dc=1485867203820:13163)
    at Ext.Inventory.create (ext-all-rtl-debug.js?_dc=1485867203820:14824)

Это из-за того, что синглтон?