APIs have classVarName, in addition to className.  

I created templates for a Java client built by Gradle, with fault tolerance from Hystrix and templated by Feign.  See: https://github.com/swps/swagger-codegen-templates

I need APIs to have `classVarName` in their mustache template context (like models do), and in addition, `toVarName` lowers the first character of the argument.
Is the problem that I am changing toVarName, or is the problem that I am assigning the new behavior to "classVarName" ?  

Would it be OK to revert line 369 and add "instanceVarName" -> toVarName(className) ?