openapi: '3.0.1'
info:
  title: 'some thing'
  version: 'v0'
paths:
  /example:
    get:
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                a:
                  type: string
                b:
                  type: number
                c:
                  type: boolean
                d:
                  allOf:
                    - type: object
                      properties:
                        a:
                          type: string
                    - type: string
      responses:
        200:
          description: 'some thing'
          content:
            application/json:
              schema:
                type: 'string'