class_docstr: Load the Market 1501 dataset.
  
  Parameters
  ----------
  items : list
      List for image names and labels.
  flag : int, default 1
      Whether to load the color image or gray image.
  transform : function, default None
      A function that takes data and label and transforms them.
class_docstr_tok: ["Load","the","Market","1501","dataset",".","Parameters","--","--","--","--","--","items",":","list","List","for","image","names","and","labels",".","flag",":","int",",","default","1","Whether","to","load","the","color","image","or","gray","image",".","transform",":","function",",","default","None","A","function","that","takes","data","and","label","and","transforms","them","."]
code: def __len__(self):
      return len(self.items)
  
imports: from mxnet.gluon.data import dataset
  from mxnet import image
label_desc: Use image node_id 3 for calling the ImageTxtDataset obj's underlying member method code with example usage: obj.__len__() and returns: len