Following Objects supports Specification Extensions which are used by some tools.

• OpenAPI
• Info
• Contact
• License
• Server
• ServerVariable
• Paths
• PathItem
• OperationObject
• ExternalDocumentation
• StyleExamples
• RequestBody
• MediaType
• Encoding
• Responses
• Response
• Callback
• Example
• Link
• Tag
• Schema
• XML
• Security Scheme
• OAUTH Flows
• OAUTH Flow
• SecurityRequirement

I will be able to add this support and send in a pull request if you are interested