Codegen removes `$` from the name

Description

codegen removes $ from the name

Swagger-codegen version

3.0.34

Swagger declaration file content or url

   "CommodityProduct": {
        "required": [
          "$type"
        ],
        "type": "object",
        "properties": {
          "$type": {
            "type": "string"
          },
...

generates

export interface CommodityProduct { 
    type: string;
...

expected:

export interface CommodityProduct { 
    $type: string;
...

Command line used for generation

java -jar ${__dirname}/swagger-codegen-cli-3.0.34.jar generate \
    -i ${config.swaggerPath} \
    -l typescript-angular \
    -o ${project} 

Steps to reproduce

just run command with such swagger file

Suggest a fix/enhancement

I have tried different --additional-properties, but it is still removing $ from the name. There should be some option to not rename keys from swagger file.

Reproduce the issue with the shown Swagger declaration and the swagger-codegen-cli 3.0.34 command using the typescript-angular generator. Start by tracing how the generator transforms the $type property name; done means generated TypeScript preserves $type instead of emitting type.