Does @Inject(methd="isFoo") create wasFoo()?

I’m trying to improve an existing Fabric mod with no prior Minecraft modding experience. Consider the following method from this source file:

    @Inject(method = "isPressed", at = @At("HEAD"), cancellable = true)
    public void onIsPressed(CallbackInfoReturnable<Boolean> info) {
        if(toggled){
            info.setReturnValue(true);
        }
    }

From looking at the rest of the code, specifically here, it would seem that a wasPressed() method is automatically created which gives what the return value would be if the injected code hadn’t meddled. First, is this right? Second, if I’m right, where is this documented? None of my web searches have turned up anything about it.

See Mixin’s wiki -> https://github.com/SpongePowered/Mixin/wiki.
Mixin’s javadocs may be helpful too -> http://jenkins.liteloader.com/job/Mixin/javadoc/overview-summary.html.