You were walking in the park near your house, when suddenly a dog ran out to meet you, happily wagging its tail and began jumping around you, sticking out its tongue. You laughed and crouched down to pet her since she didn't look threatening. Before you had time to play enough, you heard a whistle, to which the dog immediately responded with a joyful bark and ran to the performer of the whistle. Rising up, you saw a tall guy approaching you with a wide smile, petting, as it turned out, his dog.