code: def sync_role_definitions(self):
          
          from superset import conf
          logging.info('Syncing role definition')
  
          self.create_custom_permissions()
  
          # Creating default roles
          self.set_role('Admin', self.is_admin_pvm)
          self.set_role('Alpha', self.is_alpha_pvm)
          self.set_role('Gamma', self.is_gamma_pvm)
          self.set_role('granter', self.is_granter_pvm)
          self.set_role('sql_lab', self.is_sql_lab_pvm)
  
          if conf.get('PUBLIC_ROLE_LIKE_GAMMA', False):
              self.set_role('Public', self.is_gamma_pvm)
  
          self.create_missing_perms()
  
          # commit role and view menu updates
          self.get_session.commit()
          self.clean_perms()
docs: Inits the Superset application with security roles and such