function normalizeOptionValue(option) {
      if (!option) {
        return normalizeOptionValue({})
      }

      /** @type {ContentsOptions} */
      const contentsOptions = option
      /** @type {ArgsOptions} */
      const options = {
        singleline: contentsOptions.singleline || 'consistent',
        multiline: contentsOptions.multiline || 'always',
        maxEmptyLines: contentsOptions.maxEmptyLines || 0
      }
      const { blocks } = option
      if (!blocks) {
        return (element) => verifyElement(element, options)
      }

      return (element) => {
        const { name } = element
        const elementsOptions = blocks[name]
        if (elementsOptions) {
          normalizeOptionValue({
            singleline: elementsOptions.singleline || options.singleline,
            multiline: elementsOptions.multiline || options.multiline,
            maxEmptyLines:
              elementsOptions.maxEmptyLines == null
                ? options.maxEmptyLines
                : elementsOptions.maxEmptyLines
          })(element)
        } else {
          verifyElement(element, options)
        }
      }
    }
Normalizes a given option value.
@param { Options | undefined } option An option value to parse.
@returns { (element: VElement) => void } Verify function.