% \begin{function}{\draw_path_curveto:nnn}
% \begin{syntax}
% \cs{draw_path_curveto:nnn} \Arg{control1} \Arg{control2} \Arg{end}
% \end{syntax}
% Joins the current path to the \meta{end} with a curved line defined by
% cubic Bézier points \meta{control1} and \meta{control2}. The bounding box
% of the path (and image) will fully-contain the curve and control points,
% \emph{i.e.}~it may be bigger than strictly necessary to contain the curve
% \emph{alone}.
% \begin{demo}
% \draw_begin: