def validate_keys(self, constraint, keys):
    for key in keys:
      self.validate_key(constraint, key)
FileCopier is lazy, it just store requested copies, and execute them later
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/datastore/cloud_datastore_validator.py/_EntityValidator.validate_keys--crossover with--dataset/ETHPy150Open conan-io/conan/conans/client/file_copier.py/FileCopier.__call__