module ActiveSupport::Deprecation::Behavior

def arity_coerce(behavior)
  unless behavior.respond_to?(:call)
    raise ArgumentError, "#{behavior.inspect} is not a valid deprecation behavior."
  end
  if behavior.respond_to?(:arity) && behavior.arity == 2
    -> message, callstack, _, _ { behavior.call(message, callstack) }
  else
    behavior
  end
end