code: def jslink(attr1, attr2):
      """Link two widget attributes on the frontend so they remain in sync.
  
      The link is created in the front-end and does not rely on a roundtrip
      to the backend.
  
      Parameters
      ----------
      source : a (Widget, 'trait_name') tuple for the first trait
      target : a (Widget, 'trait_name') tuple for the second trait
  
      Examples
      --------
  
      >>> c = link((widget1, 'value'), (widget2, 'value'))
      """
      return Link(attr1, attr2)
  
file_path: catboost/contrib/python/ipywidgets/py2/ipywidgets/widgets/widget_link.py
imports: from .widget import Widget, register, widget_serialization
  from .widget_core import CoreWidget
  from traitlets import Unicode, Tuple, Instance, TraitError
label_desc: Use image node_id 1 for calling a global function with example usage: jslink(attr1, attr2) and returns: Link