assert2 0.3.2 and ActiveSupport 2.1.2

I've found a conflict between assert2 and ActiveSupport. Both define the method in_groups_of() with different signatures and semantics. It shows up in Ultrasphinx when I run my tests. I've reproduced it in the console, see below. Any suggests on how to force the desired in_groups_of() method?

TIA,   Jeffrey


Loading development environment (Rails 2.1.2)

a = [1, 2, 3, 4]

=> [1, 2, 3, 4]


=> [[1, 2], [3, 4]]

require 'assert2'

=> ["Assert_2_0"]


LocalJumpError: no block given   from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `each_slice'   from /usr/lib/ruby/gems/1.8/gems/assert2-0.3.1/lib/ruby_reflector.rb:829:in `each'   from /usr/lib/ruby/gems/1.8/gems/assert2-0.3.1/lib/ruby_reflector.rb:829:in `each_slice'   from /usr/lib/ruby/gems/1.8/gems/assert2-0.3.1/lib/ruby_reflector.rb:829:in `in_groups_of'   from (irb):4