docs: def experiment_download_multiple_urls(url_list):
      r"""
      References:
          http://stackoverflow.com/questions/1112343/capture-sigint-in-python
          http://stackoverflow.com/questions/16694907/download-large-file-requests
          GracefulInterruptHandler
  
      Ignore:
          import signal
          import sys
          def signal_handler(signal, frame):
                  print('You pressed Ctrl+C!')
                  sys.exit(0)
          signal.signal(signal.SIGINT, signal_handler)
          print('Press Ctrl+C')
          signal.pause()
  
      Example:
          >>> # DISABLE_DOCTEST
          >>> # UNSTABLE_DOCTEST
          >>> url_list = [
          >>>     'https://lev.cs.rpi.edu/public/installers/ibeis-win32-setup-ymd_hm-2015-08-01_16-28.exe',   # NOQA
          >>>     'https://lev.cs.rpi.edu/public/models/vgg.caffe.slice_0_30_None.pickle',
          >>>     'https://lev.cs.rpi.edu/public/models/vgg.caffe.slice_0_30_None.pickle',
          >>>     'https://lev.cs.rpi.edu/public/models/vgg.caffe.slice_0_30_None.pickle',
          >>>     'https://lev.cs.rpi.edu/public/models/vgg.caffe.slice_0_30_None.pickle',
          >>>     'https://lev.cs.rpi.edu/public/models/vgg.caffe.slice_0_30_None.pickle',
          >>>     ]
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/L10/L10_R1/S1_L10_R1_PICT0070.JPG'
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0001.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0002.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0003.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0004.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0005.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0006.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0007.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0008.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0022.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0023.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0024.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0025.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0026.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0027.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0028.JPG',
          >>>     'https://snapshotserengeti.s3.msi.umn.edu/S1/B04/B04_R1/S1_B04_R1_PICT0029.JPG'
          >>> ]
      """
      import requests
      import os
      session = requests.session()
  
      def session_download_url(url):
          filename = basename(url)
          print('[utool] Downloading url=%r to filename=%r' % (url, filename))
          spoof_header = {'user-agent': 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'}
          response = session.get(url, headers=spoof_header, stream=True)
          if response.ok:
              with open(filename, 'wb') as file_:
                  _iter = response.iter_content(chunk_size=1024)
                  for chunk in ut.ProgIter(_iter, length=-1, freq=1):
                      if chunk:  # filter out keep-alive new chunks
                          file_.write(chunk)
                          file_.flush()
                          os.fsync(file_.fileno())
          else:
              print('Error downloading file. response=%r' % (response,))
              return False
          return response.ok
  
      for url in ut.ProgressIter(url_list, 'downlaoding urls'):
          if not session_download_url(url):
              break