'Get a line and
Return the IRQ sum number
IRQ line samples:
1:     44487        341         44         72   IO-APIC   1-edge      i8042
LOC:   33549868   22394684   32474570   21855077   Local timer interrupts
FIQ:   usb_fiq'

def __sum(self, line):

    splitted_line = line.split()
    try:
        ret = sum(map(int, splitted_line[1:(self.cpu_number + 1)]))
    except ValueError:
        ret = 0
    return ret
