/usr/share/texstudio/template_Beamer.tex is in texstudio-doc 2.10.8+debian-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | \documentclass{beamer}
\usepackage{default}
\begin{document}
\end{document}
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