Check the features in this network.

def check(self, radl):
        """Check the features in this network."""

        SIMPLE_FEATURES = {
            "host": (str, None),
            "credentials.username": (str, None),
            "credentials.password": (str, None),
            "credentials.private_key": (str, None)
        }
        self.check_simple(SIMPLE_FEATURES, radl)

        if not self.getHost():
            raise RADLParseException("Ansible host must have a host", line=self.line)
        (username, password, private_key) = self.getCredentialValues()
        if not username:
            raise RADLParseException("Ansible host must have a credentials.username", line=self.line)
        if not password and not private_key:
            raise RADLParseException("Ansible host must have a credentials.password or credentials.private_key",
                                     line=self.line)