compose

# File activestorage/lib/active_storage/service/gcs_service.rb, line 139
    def compose(source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
      bucket.compose(source_keys, destination_key).update do |file|
        file.content_type = content_type
        file.content_disposition = content_disposition_with(type: disposition, filename: filename) if disposition && filename
        file.metadata = custom_metadata
      end
    end