/// <summary>
/// Initializes a new instance of the <see cref="MultilineTextAttribute"/> class. Used in derived type
/// using one line of text.
/// </summary>
/// <param name="line1">The first line of text.</param>
protected MultilineTextAttribute(string line1)
{
Assumes.NotNullOrEmpty(line1, "line1");
_line1 = line1;
}
