def translate_headers(self, environ):
        """Translate CGI-environ header names to HTTP header names."""
        for cgiName in environ:
            # We assume all incoming header keys are uppercase already.
            if cgiName in self.headerNames:
                yield self.headerNames[cgiName], environ[cgiName]
            elif cgiName[:5] == 'HTTP_':
                # Hackish attempt at recovering original header names.
                translatedHeader = cgiName[5:].replace('_', '-')
                yield translatedHeader, environ[cgiName]
Translate CGI-environ header names to HTTP header names.
cherrypy/_cpwsgi.py