I'd like to have two forest in one row. Unfortunately it is slightly over the page margin. I am new in latex. Do you have any suggestions for me?
\documentclass[a4paper,12pt,DIV=15,BCOR=12mm,oneside,numbers=noenddot,leqno,headsepline,headings=small]{scrbook}
\setlength{\parskip}{0pt}
\usepackage{linguex}
\usepackage{multicol}
\usepackage{forest}
\begin{document}
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit in~\ref{ex: test2}, At vero eos et accusam et justo duo dolores et ea in~\ref{ex: test3}.
\begin{multicols}{2}
\ex. \label{ex: test1} \a.
\begin{forest} baseline,
[
[tester3,l*=3]
[
[tester2,l*=2]
[
[tester]
[tester]
]]]
\label{ex: test2}
\end{forest}
\b.\begin{forest} baseline,
[ [ [
[tester]
[tester]
]
[tester2,l*=2]
]
[tester3,l*=3]
]
\label{ex: test3}
\end{forest}
\end{multicols}
\end{document}

