text: #!/usr/bin/python
  #
  # Copyright 2012-2013 Software freedom conservancy
  #
  # Licensed 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 base64
  from selenium.webdriver.remote.command import Command
  from selenium.webdriver.remote.webdriver import WebDriver as RemoteWebDriver
  from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
  from selenium.common.exceptions import WebDriverException
  from .service import Service
  
  class WebDriver(RemoteWebDriver):
      """
      Wrapper to communicate with PhantomJS through Ghostdriver.
  
      You will need to follow all the directions here:
      https://github.com/detro/ghostdriver
      """
  
      def __init__(self, executable_path="phantomjs",
                   port=0, desired_capabilities=DesiredCapabilities.PHANTOMJS,
                   service_args=None, service_log_path=None):
          """
          Creates a new instance of the PhantomJS / Ghostdriver.
  
          Starts the service and then creates new instance of the driver.
  
          :Args:
           - executable_path - path to the executable. If the default is used it assumes the executable is in the $PATH
           - port - port you would like the service to run, if left as 0, a free port will be found.
           - desired_capabilities: Dictionary object with non-browser specific
             capabilities only, such as "proxy" or "loggingPref".
           - service_args : A List of command line arguments to pass to PhantomJS
           - service_log_path: Path for phantomjs service to log to.
          """
          self.service = Service(executable_path, port=port,
              service_args=service_args, log_path=service_log_path)
          self.service.start()
  
          try:
              RemoteWebDriver.__init__(self,
                  command_executor=self.service.service_url,
                  desired_capabilities=desired_capabilities)
          except:
              self.quit()
              raise
  
          self._is_remote = False
  
      def quit(self):
          """
          Closes the browser and shuts down the PhantomJS executable
          that is started when starting the PhantomJS
          """
          try:
              RemoteWebDriver.quit(self)
          except:
              # We don't care about the message because something probably has gone wrong
              pass
          finally:
              self.service.stop()
  
      def __del__(self):
          try:
              self.service.stop()
          except:
              pass
  