prometheus/vendor/github.com/googleapis/gnostic/OpenAPIv2/README.md

# OpenAPI v2 Protocol Buffer Models

This directory contains a Protocol Buffer-language model
and related code for supporting OpenAPI v2.

Gnostic applications and plugins can use OpenAPIv2.proto
to generate Protocol Buffer support code for their preferred languages.

OpenAPIv2.go is used by Gnostic to read JSON and YAML OpenAPI 
descriptions into the Protocol Buffer-based datastructures 
generated from OpenAPIv2.proto.

OpenAPIv2.proto and OpenAPIv2.go are generated by the Gnostic 
compiler generator, and OpenAPIv2.pb.go is generated by 
protoc, the Protocol Buffer compiler, and protoc-gen-go, the
Protocol Buffer Go code generation plugin.