How can I add text influenced by an option after the body of an environment?

Question

I want to add text after the body of a \newenvironment after the main body of the environment. So the pseudocode would look like this:

\newenvironment{example}[2]{#1 \newline}{\newline #2}
\begin{document}
\begin{example}{This is before}{and this is after.}
    Hello World.
\end{document}

and format to:

This is before
Hello World
and this is after.