/// <summary>
/// Concatenates the given phrases and assigns the result to Theme.
/// ** Note that this will potentially modify phrase1. **
/// </summary>
/// <param name="phrase1">The first phrase.</param>
/// <param name="phrase2">The second phrase.</param>
public void CreateThemeFromPhrases(PhraseNode phrase1, PhraseNode phrase2)
{
if (phrase1 != null && !phrase1.IsEmpty())
{
phrase1.Add(phrase2);
this.Theme = phrase1;
}
else
{
this.Theme = phrase2;
}
}