Problem with importing openapi

The code tests for the swagger version and the logic is basically:

if (yaml or yml) import with swagger2

else //i.e. .json

  if (version = swagger 2.0) import with swagger2

  else return null ==> exception

The workaround for openapi files in .json format seems to be to replace this (e.g. for version 3.0.1)

{"openapi":"3.0.1"

with 

{"swagger":"2.0"

 and then to import the file.