presto-main/src/main/java/io/prestosql/connector/system/DelegatingSystemTablesProvider.java/DelegatingSystemTablesProvider/DelegatingSystemTablesProvider
class DelegatingSystemTablesProvider:    public DelegatingSystemTablesProvider(List<SystemTablesProvider> delegates)
    {
        requireNonNull(delegates, "delegates is null");
        checkArgument(delegates.size() >= 1, "empty delegates");
        this.delegates = ImmutableList.copyOf(delegates);
    }