function findContentMetadata(tileset, contentHeader) {
  const metadataJson = hasExtension(contentHeader, "3DTILES_metadata")
    ? contentHeader.extensions["3DTILES_metadata"]
    : contentHeader.metadata;

  if (!defined(metadataJson)) {
    return undefined;
  }

  if (!defined(tileset.schema)) {
    findContentMetadata._oneTimeWarning(
      "findContentMetadata-missing-root-schema",
      "Could not find a metadata schema for content metadata. For tilesets that contain external tilesets, make sure the schema is added to the root tileset.json.",
    );
    return undefined;
  }

  const classes = tileset.schema.classes ?? Frozen.EMPTY_OBJECT;
  if (defined(metadataJson.class)) {
    const contentClass = classes[metadataJson.class];
    return new ContentMetadata({
      content: metadataJson,
      class: contentClass,
    });
  }

  return undefined;
}
Check if a content has metadata, either defined in its metadata field (3D Tiles 1.1) or in
the <code>3DTILES_metadata</code> extension. If defined, get the content metadata
with the corresponding class.

@function

@param {Cesium3DTileset} tileset The tileset to query for content metadata
@param {object} contentHeader the JSON header for a {@link Cesium3DTileContent}
@return {ContentMetadata} the content metadata, or <code>undefined</code> if not found
@private
@experimental This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.