/// <summary>
/// Represents a Lesson or category of Words the user can be tested on
/// </summary>
/// <param name="name">The name of the Lesson</param>
/// <remarks>Use this for creating a new Lesson</remarks>
public Lesson(String name)
{
_name = name;
_id = Guid.NewGuid();
_words = new WordSet();
}
/// <summary>
/// Represents a Lesson or category of Words the user can be tested on
/// </summary>
public Lesson()
{
_words = new WordSet();
}