Can't get Gimme to match GregorianCalendar for verify

stub_fail_spec.rb

#I'm having a verify issue with gimme, I don't know if I've written the verify wrong or if gimme
#  does not support matches against Java classes.
#
require 'gimme'
require 'orchestrator'

java_import java.util.Calendar

describe Orchestrator do

  describe "Pull" do
    describe "Orders" do
      before :all do
        @mock_orders_service = gimme OrdersWebService
        give(@mock_orders_service).orders(anything,anything) { [] }
        @orchestrator = Orchestrator.new @mock_orders_service            #inject mock
      end

      it "uses the OrdersWebService" do
        @orchestrator.pull :orders                                       #will use mock with 2 Calendars
        verify(@mock_orders_service).orders(is_a(GregorianCalendar), is_a(GregorianCalendar))
      end
    end
  end
end
#Failures:
#
#  1) Orchestrator Pull Orders uses the OrdersWebService
#     Failure/Error: verify(@mock_orders_service).orders(is_a(GregorianCalendar), is_a(GregorianCalendar))
#     Gimme::Errors::VerificationFailedError:
#       expected orders to have been called with #<Gimme::Matchers::IsA:0x430a14ad>#<Gimme::Matchers::IsA:0x4ad38c3d>
#     # ./spec/lib/orchestrator_spec.rb:30:in `(root)'