presto-main/src/main/java/io/prestosql/metadata/SessionPropertyManager.java/SessionPropertyManager/addSystemSessionProperty
class SessionPropertyManager:    public void addSystemSessionProperty(PropertyMetadata<?> sessionProperty)
    {
        requireNonNull(sessionProperty, "sessionProperty is null");
        checkState(systemSessionProperties.put(sessionProperty.getName(), sessionProperty) == null,
                "System session property '%s' are already registered", sessionProperty.getName());
    }