private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.translate.v3.FileInputSource,
            com.google.cloud.translate.v3.FileInputSource.Builder,
            com.google.cloud.translate.v3.FileInputSourceOrBuilder>
        getFileInputSourceFieldBuilder() {
      if (fileInputSourceBuilder_ == null) {
        if (!(sourceCase_ == 2)) {
          source_ = com.google.cloud.translate.v3.FileInputSource.getDefaultInstance();
        }
        fileInputSourceBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.translate.v3.FileInputSource,
                com.google.cloud.translate.v3.FileInputSource.Builder,
                com.google.cloud.translate.v3.FileInputSourceOrBuilder>(
                (com.google.cloud.translate.v3.FileInputSource) source_,
                getParentForChildren(),
                isClean());
        source_ = null;
      }
      sourceCase_ = 2;
      onChanged();
      return fileInputSourceBuilder_;
    }
<pre>
Inline file source.
</pre>

<code>.google.cloud.translation.v3.FileInputSource file_input_source = 2;</code>
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/ImportAdaptiveMtFileRequest.java