code: public static ExternalTableDefinition of(
        List<String> sourceUris, Schema schema, FormatOptions format) {
      return newBuilder(sourceUris, schema, format).build();
    }
docs: Creates an ExternalTableDefinition object.
  
  @param sourceUris the fully-qualified URIs that point to your data in Google Cloud Storage.
  Each URI can contain one '*' wildcard character that must come after the bucket's name.
  Size limits related to load jobs apply to external data sources, plus an additional limit
  of 10 GB maximum size across all URIs.
  @param schema the schema for the external data
  @param format the source format of the external data
  @return an ExternalTableDefinition object given source URIs, schema and format
  @see <a href="https://cloud.google.com/bigquery/loading-data-into-bigquery#quota">Quota</a>
  @see <a
  href="https://cloud.google.com/bigquery/docs/reference/v2/tables#externalDataConfiguration.sourceFormat">
  Source Format</a>