How does Holden protect himself from harm as hes walking down 5th avenue?

he pretends that allie is with him. pg. 198 "And then i did something else.Every time I'd get to the end of a block I'd make believe I was talking to my brother Allie. I'd say to him, "Allie, don't let me disappear. Allie, don't let me disappear. Allie, don't let me disappear. Please, Allie." And then when I'd reach the other side of the street without disappearing, I'd thank him."