def has_role? role_name
      raise ArgumentError, '#has_role? should take a single role String or Symbol as the argument' if !role_name || role_name.kind_of?(Array)
      has_roles? role_name
    end
def has_role? role_name
      raise ArgumentError, '#has_role? should take a single role String or Symbol as the argument' if !role_name || role_name.kind_of?(Array)
      has_roles? role_name
    end
check if any (at least ONE) of the given roles have been assigned