code: def get_data_hash_diff(files, dtype=np.float64):
      """Get difference between md5 values of data
  
      Parameters
      ----------
      files: list of actual files
  
      Returns
      -------
      list
        np.array: md5 values of respective files
      """
  
      md5sums = [
          hashlib.md5(
              np.ascontiguousarray(nib.load(f).get_fdata(dtype=dtype))
          ).hexdigest()
          for f in files
      ]
  
      if len(set(md5sums)) == 1:
          return []
  
      return md5sums
  
file_path: nibabel/nibabel/cmdline/diff.py
imports: import hashlib
  import os
  import re
  import sys
  from collections import OrderedDict
  from optparse import Option, OptionParser
  import numpy
  import nibabel
  import nibabel.cmdline.utils
label_desc: Use image node_id 4 for calling a global function with example usage: get_data_hash_diff(files, dtype) and returns: md5sums, list