def remove_role role
      raise ArgumentError, '#remove_role takes a single role String or Symbol as the argument' if !role || role.kind_of?(Array)
      remove_roles role
    end
def remove_role role
      raise ArgumentError, '#remove_role takes a single role String or Symbol as the argument' if !role || role.kind_of?(Array)
      remove_roles role
    end
remove a single role