code: def update(self, other):
          '''
          Add all pileup elements from other into self.
          '''
          assert self.locus == other.locus
          self.elements.update(other.elementsf update(self, other):
          '''
          Add all pileup elements from other into self.
          '''
          assert self.locus == other.locus
          self.elements.update(other.elements)
docs: Add all pileup elements from other into self.