\def\contentI{\noindent\vrule height10pt depth0pt width30pt\hfil}
\def\contentII{\noindent\vrule height20pt depth2pt width60pt\hfil}

\def\cals@cs@width{2pt}
\def\cals@framecs@width{0pt}
\def\cals@bgcolor{}

\def\wC{100pt}
\def\wCC{200pt}

%
% Empty row
%
\cals@decor@begin
\cals@decor@end
\showbox\cals@current@cs
\show\cals@current@rs@above
\show\cals@current@rs@below

%
% One cell, no overrides
%
\cals@decor@begin
\let\cals@borderL=\relax
\let\cals@borderR=\relax
\let\cals@borderT=\relax
\let\cals@borderB=\relax
\def\cals@bgcolor{}
\cals@decor@next\wC{\contentI}
\cals@decor@end
\showbox\cals@current@cs
\show\cals@current@rs@above
\show\cals@current@rs@below

%
% Two cells, no overrides
%
\cals@decor@begin
\cals@decor@next\wC{\contentI}
\cals@decor@next\wCC{\contentII}
\cals@decor@end
\showbox\cals@current@cs
\show\cals@current@rs@above
\show\cals@current@rs@below

%
% Two cells, overrides
%
\cals@decor@begin
\def\cals@borderL{4pt}
\def\cals@borderR{6pt}
\let\cals@borderT=\relax
\let\cals@borderB=\relax
\def\cals@bgcolor{green}
\cals@decor@next\wC{\contentI}
\let\cals@borderL=\relax
\let\cals@borderR=\relax
\def\cals@borderT{8pt}
\def\cals@borderB{10pt}
\def\cals@bgcolor{}
\cals@decor@next\wCC{\contentII}
\cals@decor@end
\showbox\cals@current@cs
\show\cals@current@rs@above
\show\cals@current@rs@below