code: @GwtIncompatible("Conformance")
    public void setConformanceConfigs(List<ConformanceConfig> configs) {
      this.conformanceConfigs =
          ImmutableList.<ConformanceConfig>builder()
              .add(ResourceLoader.loadGlobalConformance(CompilerOptions.class))
              .addAll(configs)
              .build();
    }
docs: Both enable and configure conformance checks, if non-null.