code: def __init__(self, parent=None, nullable=False, default=NotSet):
      self.parent = parent
      self.types_builders = {}
      self.types_count = defaultdict(int)
      self.definitions = set()
      self.nullable = nullable
      self.default = default
  
imports: from __future__ import absolute_import
  from collections import defaultdict
  import six
  from .None import errors
  from .fields import NotSet
label_desc: Use image node_id 1 to create a new Builder object from inherited base classes: object with example: obj = Builder(parent, nullable, default)