title: How to describe nested object in Swagger API?
body: <p>I am trying to describe below data structure for response of API endpoint using Swagger API.(Swagger description is shown below)<br>
  But, I get following error.<br>
  line <code>- smallpower</code> should be object.<br>
  May I know what is wrong?</p>
  
  <p><strong>actual API return</strong></p>
  
  <pre><code>{
      "smallpower": [
          {
              "A": "A",
              "B": 11.9,
              "C": true,
              "D": "D"
          },
      {
              "A": "A",
              "B": 11.9,
              "C": true,
              "D": "D"
          },
      ],
      "oa": [
          {
              "A": "A",
              "B": 11.9,
              "C": true,
              "D": "D"
          },
      {
              "A": "A",
              "B": 11.9,
              "C": true,
              "D": "D"
          },
      ],
      "light": [
          {
              "A": "A",
              "B": 11.9,
              "C": true,
              "D": "D"
          },
      {
              "A": "A",
              "B": 11.9,
              "C": true,
              "D": "D"
          },
      ]
  }  
  </code></pre>
  
  <p><strong>Swagger API specification</strong>  </p>
  
  <pre><code>  responses:
      '200':
        description: successful operation
        content:
          application/json:
            schema:
              type: object
              properties:
                - smallpower:
                  type: object
                  schema:
                    $ref: '#/components/schemas/SmallPower'
                - oa:
                  type: object
                  schema:
                    $ref: '#/components/schemas/OA'
                - light:
                  type: object
                  schema:
                    $ref: '#/components/schemas/light'
  </code></pre>
  
  <p><strong>Updated according to Helen's comment</strong><br>
  <a href="https://i.stack.imgur.com/SeyMM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SeyMM.png" alt="enter image description here"></a></p>