docs: def image_query_record(self, imagename=None):
          """Query the image record from database, if imagename is None, all
          of the image records will be returned, otherwise only the specified
          image record will be returned."""
  
          if imagename:
              with get_image_conn() as conn:
                  result = conn.execute("SELECT * FROM image WHERE "
                                        "imagename=?", (imagename,))
                  image_list = result.fetchall()
              if not image_list:
                  obj_desc = "Image with name: %s" % imagename
                  raise exception.SDKObjectNotExistError(obj_desc=obj_desc,
                                                     modID=self._module_id)
          else:
              with get_image_conn() as conn:
                  result = conn.execute("SELECT * FROM image")
                  image_list = result.fetchall()
  
          # Map each image record to be a dict, with the key is the field name in
          # image DB
          image_keys_list = ['imagename', 'imageosdistro', 'md5sum',
                        'disk_size_units', 'image_size_in_bytes', 'type',
                        'comments']
  
          image_result = []
          for item in image_list:
              image_item = dict(zip(image_keys_list, item))
              image_result.append(image_item)
          return image_result