CompletableFuture<List<CloudBlobMetadata>> queryMetadataAsync(String partitionPath, String queryText, Timer timer)
      throws CosmosException {
    return queryMetadataAsync(partitionPath, new SqlQuerySpec(queryText), timer);
  }
Get the list of blobs in the specified partition matching the specified DocumentDB query asynchronously.
@param partitionPath the partition to query.
@param queryText the DocumentDB query to execute.
@param timer the {@link Timer} to use to record query time (excluding waiting).
@return a {@link CompletableFuture} that will eventually contain a list of {@link CloudBlobMetadata} referencing
        the matching blobs.
ambry-cloud/src/main/java/com/github/ambry/cloud/azure/CosmosDataAccessor.java