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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 _log_diff_memory_data(self, prefix, new_memory_data, old_memory_data):
 """ Computes and logs the difference in memory utilization between the given old and new memory data. """

        def _vmem_used(memory_data):
            return memory_data['machine_data'].used

        def _process_mem_percent(memory_data):
            return memory_data['process_data']['memory_percent']

        def _process_rss(memory_data):
            return memory_data['process_data']['memory_info'].rss

        def _process_vms(memory_data):
            return memory_data['process_data']['memory_info'].vms

        if new_memory_data and old_memory_data:
            log.info(
                u"%s Diff Vmem used: %s, Diff percent memory: %s, Diff rss: %s, Diff vms: %s",
                prefix,
                _vmem_used(new_memory_data) - _vmem_used(old_memory_data),
                _process_mem_percent(new_memory_data) - _process_mem_percent(old_memory_data),
                _process_rss(new_memory_data) - _process_rss(old_memory_data),
                _process_vms(new_memory_data) - _process_vms(old_memory_data),
            )