code: private FileStatus[] findAllRaw(String segmentName) throws IOException {
          assert segmentName != null && segmentName.length() > 0 : "segmentName must be non-null and non-empty";
          String pattern = String.format(NAME_FORMAT, getPathPrefix(segmentName), SUFFIX_GLOB_REGEX);
          FileStatus[] files = this.fileSystem.globStatus(new Path(pattern));
  
          if (files.length > 1) {
              throw new IllegalArgumentException("More than one file");
          }
          return files;
      }
docs: Gets an array (not necessarily ordered) of FileStatus objects currently available for the given Segment.
  These must be in the format specified by NAME_FORMAT (see EXAMPLE_NAME_FORMAT).