NullPointerException during generation

Description

Hi, I have following swagger definition

/api/v2.0/accounts/{account_id}/rebate_accounts/{rebate_account_id}:  {
post: {
parameters: [
{
description: "New rebate percent",
in: "body",
name: "body",
required: true,
type: "number"
},
{
default: "FBB1234.111",
description: "Account Id",
example: "FBB1234.111",
in: "path",
name: "account_id",
required: true,
type: "string"
}]
…

When I run generate command:

java -jar ./swagger-codegen-cli.jar generate -i http://localhost/api-docs/swagger.json -l python -o ../swagger-codegen

It fails with the following exception:

Exception in thread "main" java.lang.RuntimeException: Could not process operation:
Tag: accounts
Operation: null
Resource: post /api/v2.0/accounts/{account_id}/rebate_accounts/{rebate_account_id}
...
Exception: null
	at io.swagger.codegen.DefaultGenerator.processOperation(DefaultGenerator.java:861)
	at io.swagger.codegen.DefaultGenerator.processPaths(DefaultGenerator.java:764)
	at io.swagger.codegen.DefaultGenerator.generateApis(DefaultGenerator.java:388)
	at io.swagger.codegen.DefaultGenerator.generate(DefaultGenerator.java:700)
	at io.swagger.codegen.cmd.Generate.run(Generate.java:285)
	at io.swagger.codegen.SwaggerCodegen.main(SwaggerCodegen.java:35)
Caused by: java.lang.NullPointerException
	at io.swagger.codegen.DefaultCodegen.isDataTypeBinary(DefaultCodegen.java:2682)
	at io.swagger.codegen.DefaultCodegen.fromParameter(DefaultCodegen.java:2633)
	at io.swagger.codegen.DefaultCodegen.fromOperation(DefaultCodegen.java:2191)
	at io.swagger.codegen.DefaultGenerator.processOperation(DefaultGenerator.java:808)
	... 5 more

ver. swagger-codegen 2.2.3

Swagger declaration file content or url

Reproduce the failure with the shown swagger-codegen generate command, then trace DefaultGenerator.processOperation through DefaultCodegen.fromParameter and isDataTypeBinary, where the stack trace reports the NullPointerException. Done means the supplied Swagger definition can generate Python output without this exception.