How to use the vivisect.impemu.monitor.EmulationMonitor function in vivisect

import idaapi
import idautils

import jayutils

import vivisect
import vivisect.impemu as viv_imp
import vivisect.impemu.monitor as viv_imp_monitor
from visgraph import pathcore as vg_path

########################################################################
#
#
########################################################################

class RegMonitor(viv_imp_monitor.EmulationMonitor):
    '''
    This tracks all register changes, even if it's not currently an interesting reg
    because we need to trace register changes backwards.
    '''

    def __init__(self, regs):
        viv_imp_monitor.EmulationMonitor.__init__(self)
        self.logger = jayutils.getLogger('argracker.RegMonitor')
        self.regs = regs[:]
        self.reg_map = {}

    def prehook(self, emu, op, starteip):
        try:
            #self.logger.debug('prehook:  0x%08x', starteip)
            self.cachedRegs = emu.getRegisters()
            self.startEip = starteip