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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 get_mem_total(self):
 """Calculate the total memory in the current service unit."""

        with open('/proc/meminfo') as meminfo_file:
            for line in meminfo_file:
                key, mem = line.split(':', 2)
                if key == 'MemTotal':
                    mtot, modifier = mem.strip().split(' ')
                    return '%s%s' % (mtot, modifier[0].upper())