Update processes stats using the input method.

def update(self):
        """Update processes stats using the input method."""
        # Init new stats
        stats = self.get_init_value()

        if self.input_method == 'local':
            # Update stats using the standard system lib
            # Here, update is call for processcount AND processlist
            glances_processes.update()

            # Return the processes count
            stats = glances_processes.getcount()
        elif self.input_method == 'snmp':
            # Update stats using SNMP
            # Not avalaible
            pass

        # Update the stats
        self.stats = stats

        return self.stats