Break oversize listing line in AssertionLevel example

chapters/equations.tex

@@ -493,7 +493,8 @@ \subsection{assert}\label{assert}
 When the temperature gets out of the smaller interval, but still stays in the largest one, the user should be warned, but the simulation should continue without any further action.
 The corresponding code would be:
 \begin{lstlisting}[language=modelica]
-assert(T > 250 and T < 400, "Medium model outside full accuracy range", AssertionLevel.warning);
+assert(T > 250 and T < 400, "Medium model outside full accuracy range",
+       AssertionLevel.warning);
 assert(T > 200 and T < 500, "Medium model outside feasible region");
 \end{lstlisting}
 \end{nonnormative}