generator fails with undefined exception for petstore-full schema

[subeeshcbabu-zz]

API file : https://github.com/subeeshcbabu/swaggerize-examples/blob/master/api/petstore-full.json

Error stack trace:

undefined:48
                    body = models[param.schema.$ref.slice(param.schema.$ref.lastIndexOf('/') + 1)];
                                                   ^

TypeError: Cannot read property 'slice' of undefined
    at eval (eval at template (/generator-swaggerize/node_modules/yeoman-generator/node_modules/lodash/dist/lodash.js:6306:22), <anonymous>:48:52)
    at Function.forEach (/generator-swaggerize/node_modules/yeoman-generator/node_modules/lodash/dist/lodash.js:3298:15)
    at eval (eval at template (/generator-swaggerize/node_modules/yeoman-generator/node_modules/lodash/dist/lodash.js:6306:22), <anonymous>:30:15)
    at Function.forEach (/generator-swaggerize/node_modules/yeoman-generator/node_modules/lodash/dist/lodash.js:3298:15)
    at eval (eval at template (/generator-swaggerize/node_modules/yeoman-generator/node_modules/lodash/dist/lodash.js:6306:22), <anonymous>:17:3)
    at underscore [as _engine] (/generator-swaggerize/node_modules/yeoman-generator/lib/util/engines.js:32:30)
    at engine (/generator-swaggerize/node_modules/yeoman-generator/lib/actions/actions.js:303:10)
    at template (/generator-swaggerize/node_modules/yeoman-generator/lib/actions/actions.js:281:15)
    at /generator-swaggerize/app/index.js:372:18
    at Array.forEach (native)

Looks like param.schema.$ref becomes undefined at this line :
https://github.com/krakenjs/generator-swaggerize/blob/master/app/templates/_test_express.js#L50