old_contents: import os
  
  FILE_SIZE_MAX = 5242880
  STORAGE_PATH = 'app_data'
  
  DOC_SERV_VIEWED = [".pdf", ".djvu", ".xps"]
  DOC_SERV_EDITED = [".docx", ".xlsx", ".csv", ".pptx", ".txt"]
  DOC_SERV_CONVERT = [
      ".docm", ".doc", ".dotx", ".dotm", ".dot", ".odt",
      ".fodt", ".ott", ".xlsm", ".xls", ".xltx", ".xltm",
      ".xlt", ".ods", ".fods", ".ots", ".pptm", ".ppt",
      ".ppsx", ".ppsm", ".pps", ".potx", ".potm", ".pot",
      ".odp", ".fodp", ".otp", ".rtf", ".mht", ".html", ".htm", ".epub"
  ]
  
  DOC_SERV_TIMEOUT = 120000
  
  DOC_SERV_CONVERTER_URL = 'https://documentserver/ConvertService.ashx'
  DOC_SERV_API_URL = 'https://documentserver/web-apps/apps/api/documents/api.js'
  DOC_SERV_PRELOADER_URL = 'https://documentserver/web-apps/apps/api/documents/cache-scripts.html'
  
  EXAMPLE_DOMAIN = 'https://exampleserver/'
  
  DOC_SERV_JWT_SECRET = ''
  
  
  EXT_SPREADSHEET = [
      ".xls", ".xlsx", ".xlsm",
      ".xlt", ".xltx", ".xltm",
      ".ods", ".fods", ".ots", ".csv"
  ]
  
  EXT_PRESENTATION = [
      ".pps", ".ppsx", ".ppsm",
      ".ppt", ".pptx", ".pptm",
      ".pot", ".potx", ".potm",
      ".odp", ".fodp", ".otp"
  ]
  
  EXT_DOCUMENT = [
      ".doc", ".docx", ".docm",
      ".dot", ".dotx", ".dotm",
      ".odt", ".fodt", ".ott", ".rtf", ".txt",
      ".html", ".htm", ".mht",
      ".pdf", ".djvu", ".fb2", ".epub", ".xps"
  ]
  
  
  if os.environ.get("EXAMPLE_DOMAIN"):
      EXAMPLE_DOMAIN = os.environ.get("EXAMPLE_DOMAIN")
  if os.environ.get("DOC_SERV"):
      base = os.environ.get("DOC_SERV").rstrip('/')
      DOC_SERV_CONVERTER_URL = base + '/ConvertService.ashx'
      DOC_SERV_API_URL = base + '/web-apps/apps/api/documents/api.js'
      DOC_SERV_PRELOADER_URL = base + '/web-apps/apps/api/documents/cache-scripts.html'
new_contents: import os
  
  FILE_SIZE_MAX = 5242880
  STORAGE_PATH = 'app_data'
  
  DOC_SERV_VIEWED = [".pdf", ".djvu", ".xps"]
  DOC_SERV_EDITED = [".docx", ".xlsx", ".csv", ".pptx", ".txt"]
  DOC_SERV_CONVERT = [
      ".docm", ".doc", ".dotx", ".dotm", ".dot", ".odt",
      ".fodt", ".ott", ".xlsm", ".xls", ".xltx", ".xltm",
      ".xlt", ".ods", ".fods", ".ots", ".pptm", ".ppt",
      ".ppsx", ".ppsm", ".pps", ".potx", ".potm", ".pot",
      ".odp", ".fodp", ".otp", ".rtf", ".mht", ".html", ".htm", ".epub", ".fb2"
  ]
  
  DOC_SERV_TIMEOUT = 120000
  
  DOC_SERV_CONVERTER_URL = 'https://documentserver/ConvertService.ashx'
  DOC_SERV_API_URL = 'https://documentserver/web-apps/apps/api/documents/api.js'
  DOC_SERV_PRELOADER_URL = 'https://documentserver/web-apps/apps/api/documents/cache-scripts.html'
  
  EXAMPLE_DOMAIN = 'https://exampleserver/'
  
  DOC_SERV_JWT_SECRET = ''
  
  
  EXT_SPREADSHEET = [
      ".xls", ".xlsx", ".xlsm",
      ".xlt", ".xltx", ".xltm",
      ".ods", ".fods", ".ots", ".csv"
  ]
  
  EXT_PRESENTATION = [
      ".pps", ".ppsx", ".ppsm",
      ".ppt", ".pptx", ".pptm",
      ".pot", ".potx", ".potm",
      ".odp", ".fodp", ".otp"
  ]
  
  EXT_DOCUMENT = [
      ".doc", ".docx", ".docm",
      ".dot", ".dotx", ".dotm",
      ".odt", ".fodt", ".ott", ".rtf", ".txt",
      ".html", ".htm", ".mht",
      ".pdf", ".djvu", ".fb2", ".epub", ".xps"
  ]
  
  
  if os.environ.get("EXAMPLE_DOMAIN"):
      EXAMPLE_DOMAIN = os.environ.get("EXAMPLE_DOMAIN")
  if os.environ.get("DOC_SERV"):
      base = os.environ.get("DOC_SERV").rstrip('/')
      DOC_SERV_CONVERTER_URL = base + '/ConvertService.ashx'
      DOC_SERV_API_URL = base + '/web-apps/apps/api/documents/api.js'
      DOC_SERV_PRELOADER_URL = base + '/web-apps/apps/api/documents/cache-scripts.html'
subject: add fb2 to ConverExtList