How to get the content of a specific document version

Question

I am trying to retrieve the content of a specific version with Sharepoint API. I can get metadata like this :

{
"d": {
    "results": [
        {
            "__metadata": {
                "id": "https://sharepointtest/_api/SP.FileVersionIDVERSION",
                "uri": "https://sharepointtest/_api/SP.FileVersionIDVERSION",
                "type": "SP.FileVersion"
            },
            "CreatedBy": {
                "__deferred": {
                    "uri": "https://sharepointtest/_api/SP.FileVersionIDVERSION/CreatedBy"
                }
            },
            "CheckInComment": "",
            "Created": "2019-05-14T07:45:15Z",
            "ID": 512,
            "IsCurrentVersion": false,
            "Length": "4560528",
            "Size": 4560528,
            "Url": "_vti_history/512/Shared documents/sampleversion.odt",
            "VersionLabel": "1.0"
        }
    ]
}

Using this, does anyone know how to get it as an InputStream with Java? My function in Java is

public ContentReturn getContent() {
    InputStream content = null;
    HttpGet httpGet = new HttpGet();
    try {
        httpGet =  new HttpGet("I DON'T KNOW WHAT I SHOULD PUT HERE THIS IS THE QUESTION :)" );

                content = client.execute(httpGet).getEntity().getContent();
        content.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return new ContentReturn(content, httpGet);
}
}

Thanks by advance!!