# How to create asynchronous calls in sequence diagram?

I am using tikz-uml to create a UML sequence diagram. The sequence involves the object's life to die after an asynchronous call is made, and then it gets alive again after the response is got. Something like this:

However, i cannot recreate the same thing in in LaTeX TikZ-UML. This is what i get instead.

Here is my MWE.

\documentclass{article}
\usepackage{tikz-uml}
\begin{document}
\begin{tikzpicture}
\begin{umlseqdiag}
\umlactor[no ddots]{user}
\umlobject[no ddots]{web}
\umlobject[no ddots]{DB}
\begin{umlcall}[op={\-}, return={\-}]{user}{web}

• From a design perspective the behaviour of tikz-uml seems to make sense for me - how can I return a value to an object that does not exist anymore? – epR8GaYuh Jul 18 '18 at 20:31
• Your MWE does not compile as no language is specified. You should consider adding \usepackage[english]{babel} (or something similar to the preamble of your MWE. – epR8GaYuh Jul 18 '18 at 20:33