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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_yaml_files_at_env_root(self):
 """Return list of yaml files in env_root."""

        yaml_files = glob.glob(
            os.path.join(self.env_root, '*.yaml')
        )
        yml_files = glob.glob(
            os.path.join(self.env_root, '*.yml')
        )
        return yaml_files + yml_files