Imports System.Runtime.InteropServices

Public Interface IClass1
    Function Concater(ByVal strings As Items) As String
End Interface

<ClassInterface(ClassInterfaceType.None)> _
Public Class Class1
    Implements IClass1
    Public Function Concater(ByVal strings As Items) As String Implements IClass1.Concater
        Dim counter As Integer
        Dim sb As New Text.StringBuilder
        Dim str As String
        For Each str In strings
            sb.Append(str)
        Next
        Return sb.ToString
    End Function
End Class

<ClassInterface(ClassInterfaceType.None)> _
Public Class Items
    Implements IList
    Private mdict As New ArrayList
    Public Sub CopyTo(ByVal array As System.Array, ByVal index As Integer) Implements System.Collections.ICollection.CopyTo
        mdict.CopyTo(array, index)
    End Sub

    Public ReadOnly Property Count() As Integer Implements System.Collections.ICollection.Count
        Get
            Return mdict.Count
        End Get
    End Property

    Public ReadOnly Property IsSynchronized() As Boolean Implements System.Collections.ICollection.IsSynchronized
        Get
            Return mdict.IsSynchronized
        End Get
    End Property

    Public ReadOnly Property SyncRoot() As Object Implements System.Collections.ICollection.SyncRoot
        Get
            Return mdict.SyncRoot
        End Get
    End Property

    Public Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
        Return mdict.GetEnumerator
    End Function

    Public Function Add(ByVal value As Object) As Integer Implements System.Collections.IList.Add
        Return mdict.Add(value)
    End Function

    Public Sub Clear() Implements System.Collections.IList.Clear
        mdict.Clear()
    End Sub

    Public Function Contains(ByVal value As Object) As Boolean Implements System.Collections.IList.Contains
        Return mdict.Contains(value)
    End Function

    Public Function IndexOf(ByVal value As Object) As Integer Implements System.Collections.IList.IndexOf
        Return mdict.IndexOf(value)
    End Function

    Public Sub Insert(ByVal index As Integer, ByVal value As Object) Implements System.Collections.IList.Insert
        mdict.Insert(index, value)
    End Sub

    Public ReadOnly Property IsFixedSize() As Boolean Implements System.Collections.IList.IsFixedSize
        Get
            Return mdict.IsFixedSize
        End Get
    End Property

    Public ReadOnly Property IsReadOnly() As Boolean Implements System.Collections.IList.IsReadOnly
        Get
            Return mdict.IsReadOnly
        End Get
    End Property

    Default Public Property Item(ByVal index As Integer) As Object Implements System.Collections.IList.Item
        Get
            Return mdict.Item(index)
        End Get
        Set(ByVal Value As Object)
            mdict.Item(index) = Value
        End Set
    End Property

    Public Sub Remove(ByVal value As Object) Implements System.Collections.IList.Remove
        mdict.Remove(value)
    End Sub

    Public Sub RemoveAt(ByVal index As Integer) Implements System.Collections.IList.RemoveAt
        mdict.RemoveAt(index)
    End Sub
End Class