An example of private methods colliding in modules.

module-collision.rb

module Foo
  def foo
    blah
  end

  private def blah
    "foo"
  end
end

module Bar
  def bar
    blah
  end

  private def blah
    "bar"
  end
end

class Meep
  include Foo
  include Bar
end

puts Meep.new.foo # => "bar" 😱
puts Meep.new.bar # => "bar"