Hi,
I found false negatives on DMI_USELESS_SUBSTRING when using SpotBugs to analyze my project.

DMI_USELESS_SUBSTRING: This code invokes substring(0) on a String, which returns the original value.

String testDMI_USELESS_SUBSTRING(int index){
    StringBuilder sb = new StringBuilder();
    sb.append("}");
    return sb.substring(0);
}

Similar to #1927, it seems that SpotBugs does not do the same analysis on the StringBuilder class.