1. DomName('HTMLCanvasElement.getContext')
  2. DocsEditable()
Object getContext(String contextId, [Map attrs])

Source 

@DomName('HTMLCanvasElement.getContext')
@DocsEditable()
Object getContext(String contextId, [Map attrs]) => wrap_jso(_blink.BlinkHTMLCanvasElement.instance.getContext_Callback_2_(unwrap_jso(this), contextId, convertDartToNative_Dictionary(attrs)));