Check a line under a contextualize.

def check(self, radl):
        """Check a line under a contextualize."""

        if not radl.get_system_by_name(self.system):
            raise RADLParseException("Invalid system id '%s'" % self.system, line=self.line)
        if not radl.get_configure_by_name(self.configure):
            raise RADLParseException("Invalid configure id '%s'" % self.configure, line=self.line)