Private Function SuccessivelyThreeIdenticalDigits _
    (ByVal str As String) As Boolean
 
    If str Is Nothing OrElse str.Length < 3 Then Return False
 
    For i As Integer = 0 To str.Length - 3
        If Char.IsDigit(str(i)) Then
           If str(i) = str(i + 1) AndAlso _
              str(i + 1) = str(i + 2) Then Return True
        End If
    Next i
 
    Return False
End Function