They also serve who only stand and waite.

Thou, Richard, shalt to the Duke of Norfolk, / And tell him privily of our intent.

Our company does not seek to limit its employees from using the internet or engaging in social networking.

If you examine the last line in each method of the class, you'll notice that they all end in return this. This passes on the object to the next method in the chain. With a chainable interface, the possibilities are limitless.