FOS\UserBundle\Model\User::getRoles PHP Method

    public function getRoles()
    {
        $roles = $this->roles;
        foreach ($this->getGroups() as $group) {
            $roles = array_merge($roles, $group->getRoles());
        }
        // we need to make sure to have at least one role
        $roles[] = self::ROLE_DEFAULT;
        return array_unique($roles);
    }

 /**
  * isGranted
  *
  * @param string $grantedRole
  * @param User $user
  * @return bool
  */
 public function isGranted($grantedRole, User $user)
 {
     $grantedRole = new Role($grantedRole);
     if (count($user->getRoles())) {
         foreach ($user->getRoles() as $role) {
             $roles = $this->roleHierarchy->getReachableRoles(array(new Role($role)));
             if (in_array($grantedRole, $roles)) {
                 return true;
             }
         }
     }
     return false;
 }