old_contents: from __future__ import unicode_literals
  import os
  
  __all__ = [
      'ColorDepth',
  ]
  
  
  class ColorDepth(object):
      """
      Possible color depth values for the output.
      """
      #: One color only.
      DEPTH_1_BIT = 'DEPTH_1_BIT'
  
      #: ANSI Colors.
      DEPTH_4_BIT = 'DEPTH_4_BIT'
  
      #: The default.
      DEPTH_8_BIT = 'DEPTH_8_BIT'
  
      #: 24 bit True color.
      DEPTH_24_BIT = 'DEPTH_24_BIT'
  
      # Aliases.
      MONOCHROME = DEPTH_1_BIT
      ANSI_COLORS_ONLY = DEPTH_4_BIT
      DEFAULT = DEPTH_8_BIT
      TRUE_COLOR = DEPTH_24_BIT
  
      _ALL = [DEPTH_1_BIT, DEPTH_4_BIT, DEPTH_8_BIT, DEPTH_24_BIT]
  
      @classmethod
      def default(cls, term=''):
          """
          If the user doesn't specify a color depth, use this as a default.
          """
          if term in ('linux', 'eterm-color'):
              return cls.DEPTH_4_BIT
  
          # Check the `PROMPT_TOOLKIT_COLOR_DEPTH` environment variable.
          if os.environ.get('PROMPT_TOOLKIT_COLOR_DEPTH') in cls._ALL:
              return os.environ['PROMPT_TOOLKIT_COLOR_DEPTH']
  
          return cls.DEPTH_8_BIT
  
new_contents: from __future__ import unicode_literals
  from prompt_toolkit.utils import is_windows
  import os
  
  __all__ = [
      'ColorDepth',
  ]
  
  
  class ColorDepth(object):
      """
      Possible color depth values for the output.
      """
      #: One color only.
      DEPTH_1_BIT = 'DEPTH_1_BIT'
  
      #: ANSI Colors.
      DEPTH_4_BIT = 'DEPTH_4_BIT'
  
      #: The default.
      DEPTH_8_BIT = 'DEPTH_8_BIT'
  
      #: 24 bit True color.
      DEPTH_24_BIT = 'DEPTH_24_BIT'
  
      # Aliases.
      MONOCHROME = DEPTH_1_BIT
      ANSI_COLORS_ONLY = DEPTH_4_BIT
      DEFAULT = DEPTH_8_BIT
      TRUE_COLOR = DEPTH_24_BIT
  
      _ALL = [DEPTH_1_BIT, DEPTH_4_BIT, DEPTH_8_BIT, DEPTH_24_BIT]
  
      @classmethod
      def default(cls, term=''):
          """
          If the user doesn't specify a color depth, use this as a default.
          """
          if term in ('linux', 'eterm-color'):
              return cls.DEPTH_4_BIT
  
          # For now, always use 4 bit color on Windows 10 by default, even when
          # vt100 escape sequences with ENABLE_VIRTUAL_TERMINAL_PROCESSING are
          # supported. We don't have a reliable way yet to know whether our
          # console supports true color or only 4-bit.
          if is_windows() and 'PROMPT_TOOLKIT_COLOR_DEPTH' not in os.environ:
              return cls.DEPTH_4_BIT
  
          # Check the `PROMPT_TOOLKIT_COLOR_DEPTH` environment variable.
          if os.environ.get('PROMPT_TOOLKIT_COLOR_DEPTH') in cls._ALL:
              return os.environ['PROMPT_TOOLKIT_COLOR_DEPTH']
  
          return cls.DEPTH_8_BIT
  
subject: Use 4 bit color by default on Windows.