Get the environ dict resulting from interpreting this context.

        @param parent_environ Environment to interpret the context within,
            defaults to os.environ if None.
        @returns The environment dict generated by this context, when
            interpreted in a python rex interpreter.

def get_environ(self, parent_environ=None):
        """Get the environ dict resulting from interpreting this context.

        @param parent_environ Environment to interpret the context within,
            defaults to os.environ if None.
        @returns The environment dict generated by this context, when
            interpreted in a python rex interpreter.
        """
        interp = Python(target_environ={}, passive=True)
        executor = self._create_executor(interp, parent_environ)
        self._execute(executor)
        return executor.get_output()