anchor.diff:    checkoutShippingAddressUpdate(checkoutId: ID!, shippingAddress: AddressInput!): CheckoutShippingAddressUpdate
     checkoutShippingMethodUpdate(checkoutId: ID, shippingMethodId: ID!): CheckoutShippingMethodUpdate
     checkoutUpdateVoucher(checkoutId: ID!, voucherCode: String): CheckoutUpdateVoucher
  +  checkoutUpdateMetadata(id: ID!, input: MetaInput!): CheckoutUpdateMeta
  +  checkoutClearMetadata(id: ID!, input: MetaPath!): CheckoutClearStoredMeta
  +  checkoutUpdatePrivateMetadata(id: ID!, input: MetaInput!): CheckoutUpdatePrivateMeta
  +  checkoutClearPrivateMetadata(id: ID!, input: MetaPath!): CheckoutClearStoredPrivateMeta
     passwordReset(email: String!): PasswordReset
     setPassword(id: ID!, input: SetPasswordInput!): SetPassword
     customerCreate(input: UserCreateInput!): CustomerCreate
  
positive.code: }
  
  type CheckoutShippingMethodUpdate {
    errors: [Error!]
    checkout: Checkout
  }
  
negative.code:   checkout: Checkout
  }
  
  type CheckoutClearStoredMeta {
    errors: [Error!]
    checkout: Checkout
  }
  
  type CheckoutClearStoredPrivateMeta {
    errors: [Error!]
    checkout: Checkout
  }
  
  type CheckoutComplete {
    errors: [Error!]
    order: Order
  