gistfile1.rb

Marks-MacBook-Pro:code_scraps markjosef$ irb
irb(main):001:0> require './private_clobbering'
=> true
irb(main):002:0> obj = MyClass.new
=> #<MyClass:0x007ff8220fc680>
irb(main):003:0> obj.public_a
Public A
Private B
=> nil
irb(main):004:0> obj.public_b
Public B
Private B
=> nil
irb(main):005:0> obj.my_public_method
Public C
Private B
=> nil

private_clobbering.rb

module ModuleA

  def public_a
    puts "Public A"
    my_private_method
  end

  private

  def my_private_method
    puts "Private A"
  end

end

module ModuleB

  def public_b
    puts "Public B"
    my_private_method
  end

  private

  def my_private_method
    puts "Private B"
  end

end

class MyClass

  include ModuleA
  include ModuleB

  def my_public_method
    puts "Public C"
    my_private_method
  end

end