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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 rpc_chain_sync(server_state, new_block_height, finish_time):
 """ Flush the global RPC server cache, and tell the rpc server that we've reached the given block height at the given time. """

    rpc_srv = server_state['rpc']
    if rpc_srv is not None:
        rpc_srv.cache_flush()
        rpc_srv.set_last_index_time(finish_time)