describe Stack do
  describe 'when initialized' do
    it 'should be empty'
  end

  describe 'when empty' do
    describe 'and an element is pushed' do
      it 'should not be empty'
      it 'should have a size of 1'
    end
    describe 'and popping an element' do
      it 'should fail'
    end
  end

  describe 'with an element' do
    describe 'and popping an element' do
      it 'should return the element'
      it 'should be empty'
    end
  end
end