[Zope] ZPT and private method

Hi I have a Python product, the main class is derived from SimpleItem. I want to call an object private method, 'getSomething', from ZPT index_html of the object. I got an error like : Error Type: Undefined Error Value: You are not allowed to access getSomething in this context not found in 'here/getSomething', at line 14, column 9 The method getSomething is declared private. What am I doing wrong here? I cannot call a private method from a ZPT of the same object? Is there a way to handle this? Thanks a lot, Dragos