Import the 'setspace' package by default

latex/ots.sty

@@ -22,6 +22,20 @@
 % http://tug.ctan.org/tex-archive/macros/latex/contrib/censor/censor.pdf
 \usepackage{censor}
 
+% Use this to shrink the vertical space between lines in a ToC,
+% for example because your ToC *almost* fits all on the first
+% page and with a little shrinking you can make it work.  E.g.:
+%
+%   \begin{spacing}{0.1}
+%   \tableofcontents
+%   \end{spacing}
+%
+% You can also use this for things like double-spacing a document, etc.
+% More information at https://latex.org/forum/viewtopic.php?t=4628 and
+% https://ctan.org/pkg/setspace and especially the "Usage:" section of 
+% http://tug.ctan.org/tex-archive/macros/latex/contrib/setspace/setspace.sty.
+\usepackage{setspace}
+
 % See "An Acronym Environment for LaTeX 2e", by Tobias Oetiker:
 % http://ctan.mirrors.hoobly.com/macros/latex/contrib/acronym/acronym.pdf
 %