Friar Tuck was upset that some of his gold and food had been stolen so he posted a reward of $5,000 for the capture of Robin Hood.Sheriff Nottingham saw the reward hanging on a tree.Sheriff Nottingham set a trap in the forest and captured Robin Hood as he was riding with Little John.Sheriff Nottingham called the number listed on the reward and demanded that he be given the money.Friar Tuck refused because there was not any contract for lack of consideration.Later, Sheriff Nottingham sued Friar Tuck.

This is an example of ________________________.