Remove a namespace definition from a node.  If href is None,
        remove all of the ns definitions on that node.  The removed
        namespaces are returned as a linked list.

        Note: If any child nodes referred to the removed namespaces,
        they will be left with dangling links.  You should call
        renconciliateNs() to fix those pointers.

        Note: This method does not free memory taken by the ns
        definitions.  You will need to free it manually with the
        freeNsList() method on the returns xmlNs object.

def removeNsDef(self, href):
        """
        Remove a namespace definition from a node.  If href is None,
        remove all of the ns definitions on that node.  The removed
        namespaces are returned as a linked list.

        Note: If any child nodes referred to the removed namespaces,
        they will be left with dangling links.  You should call
        renconciliateNs() to fix those pointers.

        Note: This method does not free memory taken by the ns
        definitions.  You will need to free it manually with the
        freeNsList() method on the returns xmlNs object.
        """

        ret = libxml2mod.xmlNodeRemoveNsDef(self._o, href)
        if ret is None:return None
        __tmp = xmlNs(_obj=ret)
        return __tmp