m.rb

RUBY_DESCRIPTION # => "ruby 2.1.0dev (2013-02-28 trunk 39535) [x86_64-linux]"

module PM
  def m(a, b)
  end
end

class PC
  prepend PM

  def m(a)
  end
end

pm = PC.instance_method(:m)
pm.owner # => #<PC:0x000000015c1420>
pm.parameters # => [[:req, :a]]
PC.new.m(:a, :b) # => nil

class RC
  def m(a)
  end
end

module RM
  refine RC do # !> Refinements are experimental, and the behavior may change in future versions of Ruby!
    def m(a, b)
    end
  end
end

using RM

rm = RC.instance_method(:m)
rm.owner # => RC
rm.parameters # => [[:req, :a]]
RC.new.m(:a, :b) # => nil