code: private ModuleMetadata getFallbackMetadataForNamespace(String namespace) {
      // Assume a provide'd file to be consistent with goog.module rewriting.
      ModuleMetadata.Builder builder =
          ModuleMetadata.builder()
              .moduleType(ModuleMetadataMap.ModuleType.GOOG_PROVIDE)
              .usesClosure(true)
              .isTestOnly(false);
      builder.googNamespacesBuilder().add(namespace);
      return builder.build();
    }
docs: Gets some made-up metadata for the given Closure namespace.
  
  <p>This is used when the namespace is not part of the input so that this pass can be fault
  tolerant and still rewrite to something. Some tools don't care about rewriting correctly and
  just want the type information of this module (e.g. clutz).