ModelProject/Library/PackageCache/com.unity.2d.animation@5.1.1/Editor/Assets/SkinningModule/CopyToolbar.uxml

<?xml version="1.0" encoding="utf-8"?>
<UXML xmlns:ui="UnityEngine.UIElements" xmlns:aui="UnityEditor.U2D.Animation">
  <aui:CopyToolbar name="CopyToolbar">
    <ui:Button name="Copy" tooltip="Copy">
      <ui:Image name="CopyImage" />
    </ui:Button>
    <ui:Button name="Paste" tooltip="Paste">
      <ui:Image name="PasteImage" />
    </ui:Button>
  </aui:CopyToolbar>
</UXML>