def removeContext(anExecutableObject):
    """Remove an ExecutableObject from the current security context.

        o Remove all objects from the top of the stack "down" to the
          supplied object.

        o If the top object on the stack declares a custom security policy,
          make that policy "current".

        o If the stack is empty, or if the top declares no custom security
          policy, restore the 'default" security policy as current.
        """
