I am using org.apache.commons.exec.CommandLine and it keeps changing window paths into Linux paths

Question

I have taken over code that uses CommandLine from the jar commons-exec-1.3.jar

org.apache.commons.exec.CommandLine

This code will return a linux path \opt\prog\bin\

cmd = new CommandLine("/opt/prog/bin/");

This code will return a linux path \opt\prog\bin\

cmd = CommandLine.parse("/opt/prog/bin/");

There is this code where I can substitute / for / still returns a linux path \opt\prog\bin\

Map <String, String > map = new HashMap<String, String >();
map.put("/", "/");
cmd = CommandLine.parse("/opt/prog/bin/", map);

And then I started spit balling anything to get it working

Map <String, String > map = new HashMap<String, String >();
map.put("\\", "/");
cmd = CommandLine.parse("/opt/prog/bin/", map);
String linux2 = cmd.toString();
 map = new HashMap<String, String >();
map.put("/", "\\");
cmd = CommandLine.parse("/opt/prog/bin/",  map);
String linux3 = cmd.toString();

Nothing works, I cant believe that this code is only used to turn windows paths into Linux paths.