Countinuations of examples

In the accepted answer of the following question: Continuing an earlier theorem-like environment with amsthm & thmtools, two methods are described for continuation of examples.

I would like to use the first method to do the same thing where all examples use the following environment:

newtheorem{examp}{Example}[section]        
newenvironment{exa}[1][]{%
        begin{adjustwidth}{3mm}{3mm}
            needspace{2baselineskip}
            rule{textwidth-6mm}{.2mm} 
            begin{examp}[#1]}{
            end{examp}
            vspace*{-2mm} 
            noindent
            rule{columnwidth-6mm}{.2mm}  
        end{adjustwidth}%
}

    newtheorem*{excont}{Example continuation}
    newcommand{continuation}{??}
    newenvironment{contexa}[1]{
    begin{adjustwidth}{3mm}{3mm}
        needspace{2baselineskip}
        rule{textwidth-6mm}{.2mm} 
        renewcommand{continuation}{ref{#1}}excont[continued]}
        {{endexcont}
        vspace*{-2mm} 
        noindent
        rule{columnwidth-6mm}{.2mm}  
    end{adjustwidth}%
    }