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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 _setup(self, lines):
        '''setup required adding content from the host to the rootfs,
           so we try to capture with with ADD.
        '''
        bot.warning('SETUP is error prone, please check output.')

        for line in lines:

            # For all lines, replace rootfs with actual root /
            line = re.sub('[$]{?SINGULARITY_ROOTFS}?', 
                          '', '$SINGULARITY_ROOTFS')

            # If we have nothing left, don't continue
            if line in ['', None]:
                continue

            # If the line starts with copy or move, assume is file from host
            if re.search('(^cp|^mv)', line):
                line = re.sub('(^cp|^mv)', '', line)
                self.files.append(line)

            # If it's a general command, add to install routine
            else:
                self.install.append(line)