code: private String convertLastSeqObj(Object lastSeqObj) throws Exception {
  		if( null == lastSeqObj ) {
  			return null;
  		} else if( lastSeqObj instanceof String ) {
  			return (String)lastSeqObj;
  		} else if( lastSeqObj instanceof Number ) {
  			// Convert to string
  			return "" + lastSeqObj;
  		} else {
  			throw new Exception("Do not know how to handle parameter 'last_seq' in change feed: "+lastSeqObj.getClass());
  		}
  	}
docs: Converts the object "last_seq" found in the change feed to a String.
  In CouchDB 1.x, last_seq is an integer. In CouchDB 2.x, last_seq is a string.
  @param lastSeqObj Object retrieved from the change feed
  @return A string representing the object
  @throws Exception