# File lib/fog/aws/requests/compute/detach_classic_link_vpc.rb, line 34
        def detach_classic_link_vpc(instance_id, vpc_id, dry_run=false)
          response = Excon::Response.new
          vpc = self.data[:vpcs].find{ |v| v['vpcId'] == vpc_id }
          instance = self.data[:instances][instance_id]
          if vpc && instance
            response.status = 200
            response.body = {
              'requestId' => Fog::AWS::Mock.request_id,
              'return'    => true
            }
            unless dry_run
              instance['classicLinkSecurityGroups'] = nil
              instance['classicLinkVpcId'] = nil
            end
            response
          elsif !instance
            raise Fog::Compute::AWS::NotFound.new("The instance ID '#{instance_id}' does not exist.")
          elsif !vpc
            raise Fog::Compute::AWS::NotFound.new("The VPC '#{vpc_id}' does not exist.")
          end
        end