function test__multiple_valid_image_files()
{
$sources = array(IMG_350 => false, IMG_1024 => false);
$expected = array(IMG_350 => array('width' => 350, 'height' => 150), IMG_1024 => array('width' => 1024, 'height' => 768));
$dimensions = AMP_Image_Dimension_Extractor::extract_by_downloading_images($sources);
$this->assertEquals($expected, $dimensions);
}