assetDocument.field(EntityAdapter.P_ID, assetId.asUniqueString());
assetDocument.field(P_FIRST_CREATED, blob.getMetrics().getCreationTime().toDate());
assetDocument.field(P_COMPONENT, componentDocumentRid);
Map<String, String> blobRefs = ImmutableMap.of(localBlobStoreId, blob.getId().asUniqueString());
assetDocument.field(P_BLOB_REFS, blobRefs);
Asset asset = (Asset) sourceAsset;
assetDocument.field(P_CONTENT_TYPE, asset.getContentType());
assetDocument.field(P_PATH, asset.getPath());
// store and return asset document
return assetDocument.save();
}