/// <summary>
/// Get string representation of the chromosome by providing its expression in
/// reverse polish notation (postfix notation).
/// </summary>
///
/// <returns>Returns string representation of the genetic tree.</returns>
///
/// <remarks><para>The method returns string representation of the tree's root node
/// (see <see cref="GPTreeNode.ToString"/>).</para></remarks>
///
public override string ToString()
{
return(root.ToString());
}