Subclasses may override this method.

        If a subclass does not override this method,
        it must implement '_set_attributeName' methods
        for all Info methods.

def _setAttr(self, attr, value):
        """
        Subclasses may override this method.

        If a subclass does not override this method,
        it must implement '_set_attributeName' methods
        for all Info methods.
        """
        meth = "_set_%s" % attr
        if not hasattr(self, meth):
            raise AttributeError("No setter for attribute '%s'." % attr)
        meth = getattr(self, meth)
        meth(value)