实体框架:实体名称与属性相同时的元数据?

这是我的代码,扩展不起作用,前缀起作用:

Imports System.Web.DynamicData
Imports System.ComponentModel.DataAnnotations
<MetadataType(GetType(ExtensionsMetaData))> _
Partial Public Class Extensions

End Class
Public Class ExtensionsMetaData
Private _phones_extensions As Object
Private _prefix As Object
Private _did_flag As Object
Private _len As Object
Private _sfc_id As Object
Private _name_display As Object
Private _floor As Object
Private _room As Object
Private _phones_departments As Object
Private _phones_buildings As Object
Private _phones_phones As Object
Private _phones_restriction_classes As Object
Private _phones_tens As Object
<DisplayName("Extension")> _
Public Property extensions() As Object
    Get
        Return _phones_extensions
    End Get
    Set(ByVal value As Object)
        _phones_extensions = value
    End Set
End Property
<DisplayName("Prefix")> _
Public Property prefix As Object
    Get
        Return _prefix
    End Get
    Set(ByVal value As Object)
        _prefix = value
    End Set
End Property

我怎样才能让这个代码工作?我已经查看了所有的数据模型,它的名称似乎应该是扩展!

我收到的错误是:类型“phoneDBentities.Extensions”的关联元数据类型包含以下未知属性或字段:Extensions。请确保这些成员的名称与主类型上属性的名称匹配。