docstr: Return an instance of the SFNTWriter sub-class which is compatible
  with the specified 'flavor'.
code: def __new__(cls, *args, **kwargs):
      """Return an instance of the SFNTWriter sub-class which is compatible
      with the specified 'flavor'.
      """
      flavor = None
      if kwargs and "flavor" in kwargs:
          flavor = kwargs["flavor"]
      elif args and len(args) > 3:
          flavor = args[3]
      if cls is SFNTWriter:
          if flavor == "woff2":
              # return new WOFF2Writer object
              from fontTools.ttLib.woff2 import WOFF2Writer
  
              return object.__new__(WOFF2Writer)
      # return default object
      return object.__new__(cls)
  
imports: from io import BytesIO
  from types import SimpleNamespace
  from fontTools.misc.textTools import Tag
  from fontTools.misc import sstruct
  from fontTools.ttLib import TTLibError, TTLibFileIsCollectionError
  import struct
  from collections import OrderedDict
  import logging
label_desc: Use image node_id 1 for calling the SFNTWriter obj's underlying member method code with example usage: obj.__new__(cls) and returns: object, object