Calulator changes

I just trying to see all calculators from console but for this method I get the following error, so I just make change in Calculator Model and again check it works which result is at last..

1.9.3p125 :102 > Spree::Calculator.calculators
NoMethodError: undefined method `all' for #<Spree::Core::Environment::Calculators:0x007fe71453ce30>
	from /Users/lebin/.rvm/gems/ruby-1.9.3-p125/bundler/gems/spree-9e4cfd575319/core/app/models/spree/calculator.rb:24:in `calculators'
	from (irb):102
	from /Users/lebin/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.13/lib/rails/commands/console.rb:47:in `start'
	from /Users/lebin/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.13/lib/rails/commands/console.rb:8:in `start'
	from /Users/lebin/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.13/lib/rails/commands.rb:41:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'
1.9.3p125 :103 > 

After making changes in def self.calculators method result is .. 


1.9.3p125 :106 > Spree::Calculator.calculators
 => #<Spree::Core::Environment::Calculators:0x007fe71453ce30 @shipping_methods=[Spree::Calculator::Shipping::FlatPercentItemTotal(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::Shipping::FlatRate(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::Shipping::FlexiRate(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::Shipping::PerItem(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::Shipping::PriceSack(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime)], @tax_rates=[Spree::Calculator::DefaultTax(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime)], @promotion_actions_create_adjustments=[Spree::Calculator::FlatPercentItemTotal(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::FlatRate(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::FlexiRate(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::PerItem(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::PercentPerItem(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime), Spree::Calculator::FreeShipping(id: integer, type: string, calculable_id: integer, calculable_type: string, created_at: datetime, updated_at: datetime)]> 
1.9.3p125 :107 >