code: def filter_significance(diff, significance):
      
      changed = diff['changed']
  
      # remove individual field changes that are significant
      reduced = [{'key': delta['key'],
                  'fields': {k: v
                             for k, v in delta['fields'].items()
                             if _is_significant(v, significance)}}
                 for delta in changed]
  
      # call a key changed only if it still has significant changes
      filtered = [delta for delta in reduced if delta['fields']]
  
      diff = diff.copy()
      diff['changed'] = filtered
      return diff
docs: Prune any changes in the patch which are due to numeric changes less than this level of
      significance.