code: def add_directive_header(self, sig):
      default = self.object.default_value
      if default is Undefined:
          default_s = ""
      else:
          default_s = repr(default)
      sig = " = {}({})".format(
          self.object.__class__.__name__,
          default_s,
      )
      return super().add_directive_header(sig)
  
file_path: pythreejs/docs/sphinxext/autodoc_traits.py
imports: from collections import OrderedDict
  from traitlets import TraitType, Undefined, Container, Dict, Any, HasTraits
  from sphinx.ext.autodoc import ClassDocumenter, AttributeDocumenter
label_desc: Use image node_id 3 for calling the TraitDocumenter obj's underlying member method code with example usage: obj.add_directive_header(sig) and returns: super