An API call may be able to consume multiple formats. This format could be for example `multipart/form-data` or `application/json`. However, following the spec, these fields are mutually exclusive. The following is considered invalid by [Swagger editor](http://editor.swagger.io): ``` yaml info: title: demo version: 1.0.0 paths: /: post: consumes: - application/json - multipart/form-data parameters: - name: payload in: body schema: {} - name: attachment in: formData type: string responses: 200: description: asd swagger: '2.0' ```