text: import numpy as np
  
  class Imdb(object):
      """
      Base class for dataset loading
  
      Parameters:
      ----------
      name : str
          name of dataset
      """
      def __init__(self, name):
          self.name = name
          self.classes = []
          self.num_classes = 0
          self.image_set_index = []
          self.num_images = 0
          self.labels = None
          self.padding = 0
  
      def image_path_from_index(self, index):
          """
          load image full path given specified index
  
          Parameters:
          ----------
          index : int
              index of image requested in dataset
  
          Returns:
          ----------
          full path of specified image
          """
          raise NotImplementedError
  
      def label_from_index(self, index):
          """
          load ground-truth of image given specified index
  
          Parameters:
          ----------
          index : int
              index of image requested in dataset
  
          Returns:
          ----------
          object ground-truths, in format
          numpy.array([id, xmin, ymin, xmax, ymax]...)
          """
          raise NotImplementedError
  