code: synchronized void setLength(long length) {
          Preconditions.checkState(!this.sealed, "Cannot increase the length of a sealed SegmentChunk.");
          Preconditions.checkArgument(length >= 0, "length must be a non-negative number.");
          this.length = length;
      }
docs: Sets the length of the SegmentChunk.
  @param length The new length.