module ViewModel::ActiveRecord::ControllerBase

def access_control=(access_control)
  if instance_variable_defined?(:@access_control)
    raise ArgumentError.new("AccessControl class for Controller '#{self.name}' already set")
  end
  unless access_control.is_a?(Class) && access_control < ViewModel::AccessControl
    raise ArgumentError.new("'#{access_control.inspect}' is not a valid AccessControl")
  end
  @access_control = access_control
end