code: def get_metadata(did):
      
      try:
          asset_record = dao.get(did)
          metadata = _get_metadata(asset_record['service'])
          return Response(_sanitize_record(metadata), 200, content_type='application/json')
      except Exception as e:
          logger.error(e)
          return f'{did} asset DID is not in OceanDB', 404
docs: Get metadata of a particular asset
      ---
      tags:
        - metadata
      parameters:
        - name: did
          in: path
          description: DID of the asset.
          required: true
          type: string
      responses:
        200:
          description: successful operation.
        404:
          description: This asset DID is not in OceanDB.