Please comment on the code below;

try $\{$

BufferedReader reader $=$ new BufferedReader$($new FileReader$($new File$($graphOneFilename$)))$;

String graphString $=""$;

while $($reader$.$ready$())\{$

graphString $+=$ reader.readLine$()$;

$\}$

this.graphOne $=$ this.graphOne.edgeListToGraph$($graphString$)$;

reader.close$()$;

reader $=$ new BufferedReader$($new FileReader$($new File$($graphTwoFilename$)))$;

graphString $=""$;

while $($reader$.$ready$())\{$

graphString $+=$ reader.readLine$()$;

$\}$

this.graphTwo $=$ this.graphTwo.edgeListToGraph$($graphString$)$;

reader.close$()$;

$\}$ catch $($FileNotFoundException e$)\{$

System.err.println$("$File not found: $"+$ e$.$getMessage$())$;

$\}$ catch $($IOException e$)\{$

System.err.println$("$Error reading file: $"+$ e$.$getMessage$())$;

$\}$

int i $=0$;

while $($this$.$graphOne.numVertices$()<$ this.graphTwo.numVertices$())\{$

this.graphOne.addVertex$("$dummyVertex$"+$ i$++)$;

$\}$

i $=0$;

while $($this$.$graphTwo.numVertices$()<$ this.graphOne.numVertices$())\{$

this.graphTwo.addVertex$("$dummyVertex$"+$ i$++)$;

$\}$