get:
  description: 'Returns a pet based on ID'
  summary: 'Find pet by ID'
  operationId: getPetsById
  produces: [application/json, text/html]
  parameters: [{name: petId, in: path, description: 'ID of pet that needs to be fetched', required: true, type: array, items: {type: string}, collectionFormat: csv}]
  responses: {'200': {description: 'pet response', schema: {$ref: Pet}}, default: {description: 'error payload', schema: {$ref: ErrorModel}}}
