content: """Test fixtures."""
  
  from builtins import super
  
  import pytest
  from napalm.base.test import conftest as parent_conftest
  from napalm.base.test.double import BaseTestDouble
  from napalm.iosxr import iosxr
  from napalm.pyIOSXR.exceptions import XMLCLIError
  
  
  @pytest.fixture(scope="class")
  def set_device_parameters(request):
      """Set up the class."""
  
      def fin():
          request.cls.device.close()
  
      request.addfinalizer(fin)
  
      request.cls.driver = iosxr.IOSXRDriver
      request.cls.patched_driver = PatchedIOSXRDriver
      request.cls.vendor = "iosxr"
      parent_conftest.set_device_parameters(request)
  
  
  def pytest_generate_tests(metafunc):
      """Generate test cases dynamically."""
      parent_conftest.pytest_generate_tests(metafunc, __file__)
  
  
  class PatchedIOSXRDriver(iosxr.IOSXRDriver):
      """Patched IOS Driver."""
  
      def __init__(self, hostname, username, password, timeout=60, optional_args=None):
          super().__init__(hostname, username, password, timeout, optional_args)
  
          self.patched_attrs = ["device"]
          self.device = FakeIOSXRDevice()
  
      def is_alive(self):
          return {"is_alive": True}  # In testing everything works..
  
      def open(self):
          pass
  
  
  class FakeIOSXRDevice(BaseTestDouble):
      """IOSXR device test double."""
  
      def close(self):
          pass
  
      def make_rpc_call(self, rpc_call, encoded=True):
          filename = "{}.txt".format(self.sanitize_text(rpc_call))
          try:
              full_path = self.find_file(filename)
          except OSError:
              # Some versions of IOSXR require different form of get_facts call
              # so replicate the failure here (to ultimately force the other form)
              if "PlatformInventory" in rpc_call:
                  raise XMLCLIError
              else:
                  raise
          result = self.read_txt_file(full_path)
          if encoded:
              return str.encode(result)
          else:
              return result
  
      def show_lldp_neighbors(self):
          filename = "show_lldp_neighbors.txt"
          full_path = self.find_file(filename)
          result = self.read_txt_file(full_path)
          return result
  
      def _execute_config_show(self, show_command):
          rpc_request = "<CLI><Configuration>{show_command}</Configuration></CLI>".format(
              show_command=show_command
          )
          return self.make_rpc_call(rpc_request, encoded=False)
  