Or carry dog treats. The way to a Lab's heart is via the mouth and tummy. And yes, there are mean Labs out there. They are strong dogs, made that way so they can pack a goose back to you. My old guy, found, carried and placed a nice deer head on the steps one time. I was not pleased but he was.
I walk, with my dog, each day. There is a dog that I call Cujo that would run up and growl and froth and bark. She is held back by an invisible fence. I started carrying dog treats, and much to my dog's disappointment, would throw them over for Cujo to eat. Cujo loves treats. Cujo does not bark at us anymore, even when I do not have treats.
Milk Bone makes a teeny tiny sized dog biscuit. I believe the box has a picture of a Chihuahua (kitty dog) on it. They are easy to carry and only 5 calories each. The latter is important as Labs often have weight problems.
Or, if you want to be really bad, carry an old tennis ball and throw it. If the dog is a normal Lab, it'll go after the ball. This is beginning to sound like fun, but I'm a dog person. SQUIRREL!