VBA错误:此键已与此集合的一个元素关联

Sub TestCollection()
    Dim myCollection As New Collection
    Dim key As String
    Dim value As String
    
    ' 添加元素到集合
    key = "Key1"
    value = "Value1"
    
    If Not myCollectionExists(key) Then
        myCollection.Add value, key
    Else
        ' 键值已存在，可以选择更新现有元素的值
        myCollection(key) = value
    End If
    
    ' 添加另一个元素到集合
    key = "Key2"
    value = "Value2"
    
    If Not myCollectionExists(key) Then
        myCollection.Add value, key
    Else
        ' 键值已存在，可以选择更新现有元素的值
        myCollection(key) = value
    End If
    
    ' 访问集合中的元素
    Debug.Print myCollection("Key1")
    Debug.Print myCollection("Key2")
End Sub

Function myCollectionExists(key As String) As Boolean
    On Error Resume Next
    myCollectionExists = Not IsEmpty(myCollection(key))
    On Error GoTo 0
End Function