def headerReceived(self, name, value):
        """
        Store the given header in C{self.headers}.
        """
        name = name.lower()
        if self.isConnectionControlHeader(name):
            headers = self.connHeaders
        else:
            headers = self.headers
        headers.addRawHeader(name, value)

        Store the given header in C{self.headers}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/_newclient.py