Changing Environment Paths using D language's Phobos Library

[BoQsc]

I would like to remove/add/change Environment Paths using D 
language's Phobos.
https://en.wikipedia.org/wiki/PATH_(variable)

I saw in the documentation that there is a class file 
"std.process : environment" that has the supposed ability to 
minipulate environment variables.
https://dlang.org/library/std/process/environment.html

I couldn't find a good documentation on how to search and replace 
strings using Phobos Library. However it seems that it might be 
possbile by importing "std.array : replace" function.
https://forum.dlang.org/post/jnua50$1e4a$1@digitalmars.com
https://dlang.org/library/std/array/replace.html

So, here we are, testing if it is possible to retrieve and set 
the Environmental Variables.

> import std.stdio   : writeln;
> import std.array   : replace;
> import std.process : environment;
>
>void main(){
>
>
>	// Retrieve environment variable "path" for testing if it is 
>possible
>	// to retrieve it by using D language Phobos Library
>	auto environmentPaths = environment.get("path");
>	writeln(environmentPaths); // Works as expected: we can see the 
>output of Paths.
>	
>	// Create a new Environement variable for testing if it is 
>possible
>	// to Create it with D language Phobos Library
>	environment.opIndexAssign("variableName", "Some Random Value 
>Here");
>	auto environmentalVariable = environment.get("variableName");
>	writeln(environmentalVariable); //Unexpected: absolutely no 
>output.
	
	
	

Alright, now that we see it is possible to retrieve environmental 
variable, that's great.

However, setting the variable via "environment.opIndexAssign" 
seems to not work.
What should we do?
I don't know.