docs: def _include_environment_variables(self, program, executor_vars):
          """Define environment variables."""
          env_vars = {
              'RESOLWE_HOST_URL': self.settings_actual.get('RESOLWE_HOST_URL', 'localhost'),
          }
  
          set_env = self.settings_actual.get('FLOW_EXECUTOR', {}).get('SET_ENV', {})
          env_vars.update(executor_vars)
          env_vars.update(set_env)
  
          export_commands = ['export {}={}'.format(key, shlex.quote(value)) for key, value in env_vars.items()]
          return os.linesep.join(export_commands) + os.linesep + program