```ruby
# encoding: utf-8

shared_examples_for 'an idempotent method' do
  it 'is idempotent' do
    should equal(instance_eval(&self.class.subject))
  end
end
```

Fix "idempotent method" shared example helper
user
```ruby
# encoding: utf-8

shared_examples_for 'an idempotent method' do
  it 'is idempotent' do
    first = subject
    __memoized.delete(:subject)
    should equal(first)
  end
end
```
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