old_contents: # Licensed to the Software Freedom Conservancy (SFC) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The SFC licenses this file
  # to you under the Apache License, Version 2.0 (the
  # "License"); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  
  import pytest
  
  import unittest
  import base64
  import imghdr
  
  
  class ScreenshotTests(unittest.TestCase):
  
      def test_get_screenshot_as_base64(self):
          self._loadSimplePage()
          result = base64.decodestring(self.driver.get_screenshot_as_base64())
          self.assertEqual(imghdr.what('', result), 'png')
  
      def test_get_screenshot_as_png(self):
          self._loadSimplePage()
          result = self.driver.get_screenshot_as_png()
          self.assertEqual(imghdr.what('', result), 'png')
  
      def _pageURL(self, name):
          return self.webserver.where_is(name + '.html')
  
      def _loadSimplePage(self):
          self._loadPage("simpleTest")
  
      def _loadPage(self, name):
          self.driver.get(self._pageURL(name))
  
new_contents: # Licensed to the Software Freedom Conservancy (SFC) under one
  # or more contributor license agreements.  See the NOTICE file
  # distributed with this work for additional information
  # regarding copyright ownership.  The SFC licenses this file
  # to you under the Apache License, Version 2.0 (the
  # "License"); you may not use this file except in compliance
  # with the License.  You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing,
  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, either express or implied.  See the License for the
  # specific language governing permissions and limitations
  # under the License.
  
  import pytest
  
  import unittest
  import base64
  import imghdr
  
  
  class ScreenshotTests(unittest.TestCase):
  
      def test_get_screenshot_as_base64(self):
          self._loadSimplePage()
          result = base64.b64decode(self.driver.get_screenshot_as_base64())
          self.assertEqual(imghdr.what('', result), 'png')
  
      def test_get_screenshot_as_png(self):
          self._loadSimplePage()
          result = self.driver.get_screenshot_as_png()
          self.assertEqual(imghdr.what('', result), 'png')
  
      def _pageURL(self, name):
          return self.webserver.where_is(name + '.html')
  
      def _loadSimplePage(self):
          self._loadPage("simpleTest")
  
      def _loadPage(self, name):
          self.driver.get(self._pageURL(name))
  
subject: Update screenshot test to use updated b64decode method