code: function writeCues() {
                  var
                      ebml = {
                          "id": 0x1C53BB6B,
                          "data": cues
                      },
                      
                      cuesBuffer = new ArrayBufferDataStream(16 + cues.length * 32); // Pretty crude estimate of the buffer size we'll need
                  
                  writeEBML(cuesBuffer, blobBuffer.pos, ebml);
                  blobBuffer.write(cuesBuffer.getAsDataArray());
                  
                  // Now we know where the Cues element has ended up, we can update the SeekHead
                  seekPoints.Cues.positionEBML.data = fileOffsetToSegmentRelative(ebml.offset);
              }
docs: Write a Cues element to the blobStream using the global `cues` array of CuePoints (use addCuePoint()).
  The seek entry for the Cues in the SeekHead is updated.