class_docstr: Button widget.
  
  This widget has an `on_click` method that allows you to listen for the
  user clicking on the button.  The click event itself is stateless.
  
  Parameters
  ----------
  description: str
     description displayed on the button
  icon: str
     font-awesome icon names, without the 'fa-' prefix
  disabled: bool
     whether user interaction is enabled
class_docstr_tok: ["Button","widget",".","This","widget","has","an","`","on_click","`","method","that","allows","you","to","listen","for","the","user","clicking","on","the","button",".","The","click","event","itself","is","stateless",".","Parameters","--","--","--","--","--","description",":","str","description","displayed","on","the","button","icon",":","str","font-awesome","icon","names",",","without","the","'fa-","'","prefix","disabled",":","bool","whether","user","interaction","is","enabled"]
docstr: Strip 'fa-' if necessary'
docstr_tok: ["Strip","'fa-","'","if","necessary","'"]
code: def _validate_icon(self, proposal):
      """Strip 'fa-' if necessary'"""
      value = proposal["value"]
      if "fa-" in value:
          deprecation(
              "icons names no longer need 'fa-', "
              "just use the class names themselves (for example, 'gear spin' instead of 'fa-gear fa-spin')",
              internal=[
                  "ipywidgets/widgets/",
                  "traitlets/traitlets.py",
                  "/contextlib.py",
              ],
          )
          value = value.replace("fa-", "")
      return value
  
file_path: catboost/contrib/python/ipywidgets/py3/ipywidgets/widgets/widget_button.py
imports: from .utils import deprecation
  from .domwidget import DOMWidget
  from .widget import CallbackDispatcher, register, widget_serialization
  from .widget_core import CoreWidget
  from .widget_style import Style
  from .trait_types import Color, InstanceDict
  from traitlets import Unicode, Bool, CaselessStrEnum, Instance, validate, default
label_desc: Use image node_id 2 for calling the Button obj's underlying member method code with example usage: obj._validate_icon(proposal) and returns: value