WordPress/wp-includes/js/tinymce/plugins/hr/plugin.min.js

tinymce.PluginManager.add("hr",function(a){a.addCommand("InsertHorizontalRule",function(){a.execCommand("mceInsertContent",!1,"<hr />")}),a.addButton("hr",{icon:"hr",tooltip:"Horizontal line",cmd:"InsertHorizontalRule"}),a.addMenuItem("hr",{icon:"hr",text:"Horizontal line",cmd:"InsertHorizontalRule",context:"insert"})});