import com.slack.api.Slack;
import com.slack.api.methods.response.files.FilesUploadV2Response;

Slack slack = Slack.getInstance();

// Single file upload with highlight_type
FilesUploadV2Response response = slack.methods(token).filesUploadV2(r -> r
    .channel("C0123456789")
    .file(new File("./image.png"))
    .filename("image.png")
    .title("Image Upload")
    .highlightType("png")
    .initialComment("Uploaded with highlight_type for optimistic rendering")
);

// Multiple file uploads with highlight_type
FilesUploadV2Response response = slack.methods(token).filesUploadV2(r -> r
    .channel("C0123456789")
    .uploadFiles(Arrays.asList(
        FilesUploadV2Request.UploadFile.builder()
            .file(new File("./photo.jpg"))
            .filename("photo.jpg")
            .title("Photo")
            .highlightType("jpg")
            .build(),
        FilesUploadV2Request.UploadFile.builder()
            .file(new File("./diagram.png"))
            .filename("diagram.png")
            .title("Diagram")
            .highlightType("png")
            .build()
    ))
    .initialComment("Multiple files with highlight_type")
);