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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 is_insertion(self):
 """ Does this variant represent the insertion of nucleotides into the reference genome? """

        # An insertion would appear in a VCF like C>CT, so that the
        # alternate allele starts with the reference nucleotides.
        # Since the nucleotide strings may be normalized in the constructor,
        # it's worth noting that the normalized form of this variant would be
        # ''>'T', so that 'T'.startswith('') still holds.
        return (len(self.ref) < len(self.alt)) and self.alt.startswith(self.ref)