Selective Generation doesn't work properly when option is appended

Using version 2.1.6

Commands

java -Dmodels -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate \ -i http://petstore.swagger.io/v2/swagger.json \ -l java \ -o samples/client/petstore/java

And

java -Dmodels=User,Pet -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate \ -i http://petstore.swagger.io/v2/swagger.json \ -l java \ -o samples/client/petstore/java

work according to the documentation i.e. Example 1. generates all models only. Example 2 generates Pet and User models only.

However, if the -Dmodels option is appended on the end instead e.g.

java -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate \ -i http://petstore.swagger.io/v2/swagger.json \ -l java \ -o samples/client/petstore/java \ -Dmodels

Then for example 1. It will generate everything and for example 2. it will generate the first model in the list, so in this case, it will only generate the User model.

This is problematic as scripts which wrap java -jar /path/to/swagger-codegen-cli.jar such as homebrew install of swagger codegen don't allow the option to be passed in before -jar

Reproduce the two documented commands and the appended -Dmodels form using modules/swagger-codegen-cli/target/swagger-codegen-cli.jar. Trace how the CLI parses -Dmodels before and after -jar; done when both positions produce the same selected models, including all models when no value is supplied.