code: function add(item) {
  			var newEnd = (end + 1) % BUF_SIZE;
  
  			if(end >= 0 && newEnd === begin) {
  				throw Error('Buffer overflow: Buffer exceeded max size: ' + BUF_SIZE);
  			}
  			
  			buffer[newEnd] = item;
  			end = newEnd;
  		}
docs: Add item to buffer