core/src/in/srain/cube/request/RequestData.java
@SuppressWarnings({"unused"})
    public RequestData addFile(String fieldName, String uploadFile, String fileName) {
        addFile(fieldName, new File(uploadFile), fileName);
        return this;
    }
@SuppressWarnings({"unused"})
    public RequestData addFile(String fieldName, String uploadFile, String fileName) {
        addFile(fieldName, new File(uploadFile), fileName);
        return this;
    }
add file to be uploaded

@param fieldName
@param uploadFile
@param fileName   if provided, will use this as filename
@return