class_docstr: FiftyOne App configuration settings.
class_docstr_tok: ["FiftyOne","App","configuration","settings","."]
code: def _init(self):
      supported_color_bys = {"field", "instance", "value"}
      default_color_by = "field"
      if self.color_by not in supported_color_bys:
          logger.warning(
              "Invalid color_by=%s. Must be one of %s. Defaulting to '%s'",
              self.color_by,
              supported_color_bys,
              default_color_by,
          )
          self.color_by = default_color_by
  
      supported_sidebar_modes = {"all", "best", "fast"}
      default_sidebar_mode = "best"
      if self.sidebar_mode not in supported_sidebar_modes:
          logger.warning(
              "Invalid sidebar_mode=%s. Must be one of %s. Defaulting to '%s'",
              self.sidebar_mode,
              supported_sidebar_modes,
              default_sidebar_mode,
          )
          self.sidebar_mode = default_sidebar_mode
  
      supported_themes = {"browser", "dark", "light"}
      default_theme = "browser"
      if self.theme not in supported_themes:
          logger.warning(
              "Invalid theme=%s. Must be one of %s. Defaulting to '%s'",
              self.theme,
              supported_themes,
              default_theme,
          )
          self.theme = default_theme
  
      if self.grid_zoom < 0 or self.grid_zoom > 10:
          logger.warning(
              "`grid_zoom` must be in [0, 10]; found %d", self.grid_zoom
          )
          self.grid_zoom = 5
  
      if "MAPBOX_TOKEN" in os.environ:
          try:
              _set_nested_dict_value(
                  self.plugins,
                  "map.mapboxAccessToken",
                  os.environ["MAPBOX_TOKEN"],
              )
          except Exception as e:
              logger.warning("Failed to set mapbox token: %s", e)
  
imports: import logging
  import os
  import pytz
  import eta
  import eta.core.config
  import fiftyone.constants
  import fiftyone.core.utils
label_desc: Use image node_id 3 for calling the AppConfig obj's underlying member method code with example usage: obj._init() without return types