Expanding and Collapsing table view cells in ios

Find a great code for expanding and collapsing table view on apple developer webiste. This is the link:
https://developer.apple.com/library/ios/samplecode/TableViewUpdates/Introduction/Intro.html


"TableViewUpdates" demonstrates how you can use animated updates to open and close sections of a table view for viewing, where each section represents a play, and each row contains a quotation from the play. It also uses gesture recognizers to respond to user input: * A UITapGestureRecognizer to allow tapping on the section headers to expand the section; * A UIPinchGestureRecognizer to allow dynamic changes to the height of table view rows; and * A UILongPressGestureRecognizer to allow press-and-hold on table view cells to initiate an email of the quotation.