@Override
    public boolean exists(final String location) {
        return this.listStatuses(location).length > 0;
    }
@param pattern refers directory or a set of files
@return a non-null array of the files and directories the pattern refers as of {@link Storage#ls(String)}
hadoop-gremlin/src/main/java/org/apache/tinkerpop/gremlin/hadoop/structure/io/FileSystemStorage.java