Help to revise: We also address the problem of interchange of limits under the aforementioned policies,
which justifies the stationary performance of the diffusion limit as a valid approximation to that of the original system under respective policies. 
Methodologically, this study contributes to the application of the BIGSTEP method for constructing control policy to optimize stationary performance and the recipe for justifying the interchange of limits in the heavy-traffic analysis of stochastic processing networks. Provide two versions of response separated with exactly 6 asterisk symbols: ******.
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