expected:<emocleW[]> but was:<emocleW[ ]>
I don't have ideas what's this problem is about?

public class SpinWords {

public String spinWords(String sentence) {
    String[] str = sentence.split(" ");
    String result = "";
    for(int i = 0; i<str.length;i++){
        if(str[i].length()>=5){
            result+=new StringBuilder(str[i]).reverse().toString()+" ";
        }
        else{
            result+=str[i]+" ";
        }
    }
    return result.trim()+" ";
}

}