code: def __getitem__(self, key):
      arr = self.npz_file[key]
      return cupy.array(arr)
  
file_path: cupy/cupy/_io/npz.py
imports: import warnings
  import numpy
  import cupy
label_desc: Use image node_id 4 for calling the NpzFile obj's underlying member method code with example usage: obj.__getitem__(key) and returns: cupy