%
%
\def\cals@cs@width{2pt}
\def\cals@bgcolor{green}

%
% cals@cs@outone:
% #1: cell width
% #2: left border width
% #3: background color
%
%
% test1: everything disabled
%
\setbox0=\hbox{\cals@cs@outOne\relax{0pt}{}%
\show\cals@lastLeftWidth
}
\showbox0

%
% test2: everything specified
%
\setbox0=\hbox{\cals@cs@outOne{50pt}{4pt}{red}%
\show\cals@lastLeftWidth
}
\showbox0
%
% test3: use defaults for everything
%
\setbox0=\hbox{\cals@cs@outOne{100pt}\relax\relax%
\show\cals@lastLeftWidth
}
\showbox0
%
% test4: background color ignored if no cell width
%
\setbox0=\hbox{\cals@cs@outOne\relax{2pt}{green}}
\showbox0
%
% test5: defaults are no colors, no borders
%
\def\cals@cs@width{0pt}
\def\cals@bgcolor{}
\setbox0=\hbox{\cals@cs@outOne{300pt}\relax\relax}
\showbox0
%
% test6: cell width: 0pt != \relax
%
\setbox0=\hbox{\cals@cs@outOne{0pt}{0pt}{}}
\showbox0

%
% test7: only \relax
% (Bug hunting for a space)
%
\setbox0=\hbox{\cals@cs@outOne\relax\relax\relax}
\showbox0