```ruby
require 'image_bank'

describe ImageDownloaderAdapter::Base do
  let(:source_dir) { @source_dir }
  let(:target_bank) { ImageBank.new(@target_dir) }

  it 'should download img tag' do
    file = File.join(source_dir, 'basic img.gif')
    expect(target_bank.contains? file).to be(true)
  end

  it 'should download lazily loaded images' do
    files = [
      'lazy image 1.png',
      'lazy image 2.png',
      'lazy image 3.png',
      'lazy image 4.png',
      'lazy image 5.png',
      'lazy image 6.png'
    ].map { |file| File.join(source_dir, file) }

    files.each { |file| expect(target_bank.contains? file).to be(true) }
  end

  it 'should download elements with background-image property in stylesheet' do
    file = File.join(source_dir, 'background stylesheet.png')
    expect(target_bank.contains? file).to be(true)
  end

  xit 'should download img tags with srcset in scheme http' do
  end

  xit 'should download img tags with embedded images' do
  end

  xit 'should download elements with background property in style attr' do
  end

  xit 'should download elements with background-image property in style attr' do
  end

  xit 'should download elements with background property in stylesheet' do
  end
end
```

Implement elements with background property in style attr spec
user
```ruby
require 'image_bank'

describe ImageDownloaderAdapter::Base do
  let(:source_dir) { @source_dir }
  let(:target_bank) { ImageBank.new(@target_dir) }

  it 'should download img tag' do
    file = File.join(source_dir, 'basic img.gif')
    expect(target_bank.contains? file).to be(true)
  end

  it 'should download lazily loaded images' do
    files = [
      'lazy image 1.png',
      'lazy image 2.png',
      'lazy image 3.png',
      'lazy image 4.png',
      'lazy image 5.png',
      'lazy image 6.png'
    ].map { |file| File.join(source_dir, file) }

    files.each { |file| expect(target_bank.contains? file).to be(true) }
  end

  it 'should download elements with background-image property in stylesheet' do
    file = File.join(source_dir, 'background stylesheet.png')
    expect(target_bank.contains? file).to be(true)
  end

  xit 'should download img tags with srcset in scheme http' do
  end

  xit 'should download img tags with embedded images' do
  end

  xit 'should download elements with background-image property in style attr' do
  end

  it 'should download elements with background property in style attr' do
    file = File.join(source_dir, 'background style.png')
    expect(target_bank.contains? file).to be(true)
  end
end
```
assistant