[codegen]{ze-ph} Lack of implementation for http HEAD method in ZendExpressivePathHandlerServerCodegen

Description

During generation of ze-ph code , codegen throws exception:

Exception in thread "main" java.lang.RuntimeException: Could not generate api file for '/servers' at io.swagger.codegen.DefaultGenerator.generateApis(DefaultGenerator.java:463) at io.swagger.codegen.DefaultGenerator.generate(DefaultGenerator.java:666) at io.swagger.codegen.cmd.Generate.run(Generate.java:234) at io.swagger.codegen.SwaggerCodegen.main(SwaggerCodegen.java:41) Caused by: java.lang.RuntimeException: Unknown HTTP Method HEAD not allowed at io.swagger.codegen.languages.ZendExpressivePathHandlerServerCodegen.postProcessOperations(ZendExpressivePathHandlerServerCodegen.java:150) at io.swagger.codegen.DefaultGenerator.processOperations(DefaultGenerator.java:885) at io.swagger.codegen.DefaultGenerator.generateApis(DefaultGenerator.java:380) ... 3 more

Swagger-codegen version

swagger-codegen-cli-2.2.2

Command line used for generation

java -jar swagger-codegen-cli-2.2.2.jar generate -i http://host:port/some-service/swagger.json -l ze-ph -o /tmp/ze-ph

Suggest a fix/enhancement

Implement code for missing http methods in ZendExpressivePathHandlerServerCodegen.java

Start in ZendExpressivePathHandlerServerCodegen.java, especially postProcessOperations, and reproduce the failure with the supplied swagger-codegen-cli command using a definition containing HEAD. Done means ze-ph generation no longer throws “Unknown HTTP Method HEAD” and the generated /servers API is produced.