public static bool Equals([CanBeNull] MessagePart left, [CanBeNull] MessagePart right)
 {
     return(string.Equals(left?.ToString(), right?.ToString()));
 }
 protected virtual void ToPlainText([NotNull] StringBuilder builder, [NotNull] MessagePart innerPart, [CanBeNull] string shift = null)
 {
     innerPart.ToPlainText(builder, shift);
 }
 public bool Equals([CanBeNull] MessagePart obj)
 {
     return(Equals(this, obj));
 }
 protected virtual void ToHtml([NotNull] StringBuilder builder, [NotNull] MessagePart innerPart)
 {
     innerPart.ToHtml(builder);
 }