This is a thread-safe code?
 This code may throw an exception?

       var sourceArray = Data;
        var array = new String[sourceArray.Count];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = Data[i][0];
        }
        return array;
This is a thread-safe code?
===

 This code may throw an exception?

       var sourceArray = Data;
        var array = new String[sourceArray.Count];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = Data[i][0];
        }
        return array;