old_contents: import os
  
  from astropy.version import version as astropy_version
  
  # For Astropy 3.0 and later, we can use the standalone pytest plugin
  if astropy_version < '3.0':
      from astropy.tests.pytest_plugins import *  # noqa
      del pytest_report_header
      ASTROPY_HEADER = True
  else:
      try:
          from pytest_astropy_header.display import PYTEST_HEADER_MODULES, TESTED_VERSIONS
          ASTROPY_HEADER = True
      except ImportError:
          ASTROPY_HEADER = False
  
  
  def pytest_configure(config):
  
      if ASTROPY_HEADER:
  
          config.option.astropy_header = True
  
          # Customize the following lines to add/remove entries from the list of
          # packages for which version numbers are displayed when running the tests.
          PYTEST_HEADER_MODULES.pop('Pandas', None)
          PYTEST_HEADER_MODULES['scikit-image'] = 'skimage'
  
          from . import __version__
          packagename = os.path.basename(os.path.dirname(__file__))
          TESTED_VERSIONS[packagename] = __version__
  
  # Uncomment the last two lines in this block to treat all DeprecationWarnings as
  # exceptions. For Astropy v2.0 or later, there are 2 additional keywords,
  # as follow (although default should work for most cases).
  # To ignore some packages that produce deprecation warnings on import
  # (in addition to 'compiler', 'scipy', 'pygments', 'ipykernel', and
  # 'setuptools'), add:
  #     modules_to_ignore_on_import=['module_1', 'module_2']
  # To ignore some specific deprecation warning messages for Python version
  # MAJOR.MINOR or later, add:
  #     warnings_to_ignore_by_pyver={(MAJOR, MINOR): ['Message to ignore']}
  # from astropy.tests.helper import enable_deprecations_as_exceptions  # noqa
  # enable_deprecations_as_exceptions()
  
new_contents: import os
  import warnings
  
  from astropy.version import version as astropy_version
  
  # For Astropy 3.0 and later, we can use the standalone pytest plugin
  if astropy_version < '3.0':
      from astropy.tests.pytest_plugins import *  # noqa
      del pytest_report_header
      ASTROPY_HEADER = True
  else:
      try:
          from pytest_astropy_header.display import PYTEST_HEADER_MODULES, TESTED_VERSIONS
          ASTROPY_HEADER = True
      except ImportError:
          ASTROPY_HEADER = False
  
  # Import check for matplotlib
  try:
      import matplotlib
  except ImportError:
      HAS_MATPLOTLIB = False
  else:
      HAS_MATPLOTLIB = True
  
  
  
  def pytest_configure(config):
  
      if HAS_MATPLOTLIB:
          with warnings.catch_warnings():
              warnings.simplefilter('ignore')
              matplotlib.use('Agg')
  
      if ASTROPY_HEADER:
  
          config.option.astropy_header = True
  
          # Customize the following lines to add/remove entries from the list of
          # packages for which version numbers are displayed when running the tests.
          PYTEST_HEADER_MODULES.pop('Pandas', None)
          PYTEST_HEADER_MODULES['scikit-image'] = 'skimage'
  
          from . import __version__
          packagename = os.path.basename(os.path.dirname(__file__))
          TESTED_VERSIONS[packagename] = __version__
  
  # Uncomment the last two lines in this block to treat all DeprecationWarnings as
  # exceptions. For Astropy v2.0 or later, there are 2 additional keywords,
  # as follow (although default should work for most cases).
  # To ignore some packages that produce deprecation warnings on import
  # (in addition to 'compiler', 'scipy', 'pygments', 'ipykernel', and
  # 'setuptools'), add:
  #     modules_to_ignore_on_import=['module_1', 'module_2']
  # To ignore some specific deprecation warning messages for Python version
  # MAJOR.MINOR or later, add:
  #     warnings_to_ignore_by_pyver={(MAJOR, MINOR): ['Message to ignore']}
  # from astropy.tests.helper import enable_deprecations_as_exceptions  # noqa
  # enable_deprecations_as_exceptions()
  
subject: Add setting the mpl backend in conftest