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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 get_sigmasqs(self, instruments=None):
 		""" 		Return dictionary of single-detector sigmas for each row in the 		table. 		"""

		if len(self):
			if not instruments:
				instruments = map(str, \
					instrument_set_from_ifos(self[0].ifos))
			return dict((ifo, self.get_sigmasq(ifo))\
				    for ifo in instruments)
		else:
			return dict()