# File lib/bio/db/sam/pileup.rb, line 80
  def consensus
      if @consensus.nil?
        max = self.non_refs.values.max
        if (self.ref_count / self.coverage) > 0.5
          @consensus = self.ref_base 
        elsif self.ref_count > max
          @consensus = self.ref_base
        else
          arr = self.non_refs.select {|k,v| v == max }
          bases = arr.collect {|b| b[0].to_s }
          bases << self.ref_base if self.ref_count == max
          @consensus = bases.sort.join
        end
      end
      @consensus
  end