def METHOD_NAME(self):
    imagePath = datastore.fetch(
        'sample_jp2k_33003_TCGA-CV-7242-11A-01-TS1.1838afb1-9eee-'
        '4a70-9ae3-50e3ab45e242.svs')
    source = large_image.open(imagePath)
    tileMetadata = source.getMetadata()
    params = {
        'region': {
            'width': min(10000, tileMetadata['sizeX']),
            'height': min(10000, tileMetadata['sizeY']),
        },
        'output': {
            'maxWidth': 480,
            'maxHeight': 480,
        },
        'encoding': 'PNG',
    }
    image, mimeType = source.getRegion(**params)
    assert image[:len(utilities.PNGHeader)] == utilities.PNGHeader