_do_text(self, node) -> None
        Process a text or CDATA node.  Render various special characters
        as their C14N entity representations.

def _do_text(self, node):
        '''_do_text(self, node) -> None
        Process a text or CDATA node.  Render various special characters
        as their C14N entity representations.'''
        if not _in_subset(self.subset, node): return
        s = string.replace(node.data, "&", "&amp;")
        s = string.replace(s, "<", "&lt;")
        s = string.replace(s, ">", "&gt;")
        s = string.replace(s, "\015", "&#xD;")
        if s: self.write(s)