How to use the munch.ITSampleData function in munch

if self.flags & 0x20:
			if self.susbeg > self.susend:
				print "WARNING: Susloop start is greater than susloop end"
			if self.susend > self.length:
				print "WARNING: Susloop end is greater than length"
		
		if self.length == 0:
			if (self.flags & 1):
				print "WARNING: Sample data is supposed to exist but length is 0."
				self.flags &= ~1
		
		if (self.flags & 1):
			fp.seek(smpptr)
			if smpptr == 0:
				print "WARNING: Many trackers/players don't load sampledata with a pointer of 0."
			self.smpdata = ITSampleData(self, fp, self.length, self.cvt, self.flags)
		elif smpptr != 0:
			print "WARNING: Sample pointer is nonzero but bit 0 of flags is clear."
			print "Either your tracker is broken, or you've packed this already."
			self.smpdata = None
		
		self.currently_used = False