As a learning exercise, I'm leverage this Medium Article to create a React app which uses the "oidc-react" library to manage user identity

Within the article, the author instantiates the "UserManager" class in his own class constructor (see line #8 in screenshot) But before doing so, appears to "reference" it (see line #5 in screenshot). Being somewhat new to Javascript, I can't figure out why he's doing that. I experimentally removed line #5, and doesn't seem to have effect. Is this some sort of best practice ? Just trying to learn...