Hi,
I thought it should be false negatives on IO_INEFFICIENT_INDEX_OF when using SpotBugs to analyze my project.

IO_INEFFICIENT_INDEX_OF: This code passes a constant string of length 1 to String.indexOf(). It is more efficient to use the integer implementations of String.indexOf(). f. e. call myString.indexOf('.') instead of myString.indexOf(".")

void testIIO_INEFFICIENT_INDEX_OF(int index){
    StringBuilder sb = new StringBuilder();
    int lastIndex = sb.indexOf(">", index);
}

It seems that SpotBugs does not do the same analysis on the StringBuilder class. Is it more efficient to use StringBuilder indexOf('.') than StringBuilder indexOf(".")？
Similar to #1928