defload_data(root_dir:Optional[str]=None)->DirDataset:"""Load and return the NIH Chest X-ray dataset. Args: root_dir: The path to store the downloaded data. When `path` is not provided, the data will be saved into `fastestimator_data` under the user's home directory. Returns: train_data """ifroot_dirisNone:root_dir=os.path.join(str(Path.home()),'fastestimator_data','NIH_Chestxray')else:root_dir=os.path.join(os.path.abspath(root_dir),'NIH_Chestxray')os.makedirs(root_dir,exist_ok=True)image_extracted_path=os.path.join(root_dir,'images')ifnotos.path.exists(image_extracted_path):# download datalinks=['https://nihcc.box.com/shared/static/vfk49d74nhbxq3nqjg0900w5nvkorp5c.gz','https://nihcc.box.com/shared/static/i28rlmbvmfjbl8p2n3ril0pptcmcu9d1.gz','https://nihcc.box.com/shared/static/f1t00wrtdk94satdfb9olcolqx20z2jp.gz','https://nihcc.box.com/shared/static/0aowwzs5lhjrceb3qp67ahp0rd1l1etg.gz','https://nihcc.box.com/shared/static/v5e3goj22zr6h8tzualxfsqlqaygfbsn.gz','https://nihcc.box.com/shared/static/asi7ikud9jwnkrnkj99jnpfkjdes7l6l.gz','https://nihcc.box.com/shared/static/jn1b4mw4n6lnh74ovmcjb8y48h8xj07n.gz','https://nihcc.box.com/shared/static/tvpxmn7qyrgl0w8wfh9kqfjskv6nmm1j.gz','https://nihcc.box.com/shared/static/upyy3ml7qdumlgk2rfcvlb9k6gvqq2pj.gz','https://nihcc.box.com/shared/static/l6nilvfa9cg3s28tqv1qc1olm3gnz54p.gz','https://nihcc.box.com/shared/static/hhq8fkdgvcari67vfhs7ppg2w6ni4jze.gz','https://nihcc.box.com/shared/static/ioqwiy20ihqwyr8pf4c24eazhh281pbu.gz']data_paths=[os.path.join(root_dir,"images_{}.tar.gz".format(x))forxinrange(len(links))]foridx,(link,data_path)inenumerate(zip(links,data_paths)):_download_data(link,data_path,idx,len(links))# extract dataforidx,data_pathinenumerate(data_paths):print("Extracting {}, file {} / {}".format(data_path,idx+1,len(links)))withtarfile.open(data_path)asimg_tar:img_tar.extractall(root_dir)returnDirDataset(image_extracted_path,file_extension='.png',recursive_search=False)