docs: def delete_file(self, path, prefixed_path, source_storage):
          """
          Checks if the target file should be deleted if it already exists
          """
          if isinstance(self.storage, CumulusStorage):
              if self.storage.exists(prefixed_path):
                  try:
                      etag = self.storage._get_object(prefixed_path).etag
                      digest = "{0}".format(hashlib.md5(source_storage.open(path).read()).hexdigest())
                      if etag == digest:
                          self.log(u"Skipping '{0}' (not modified based on file hash)".format(path))
                          return False
                  except:
                      raise
          return super(Command, self).delete_file(path, prefixed_path, source_storage)