code: def count_reads(self, l):
          
          
          if self.__paired:
              cmd = [self.__samtools, 'view', '-c', '-f', '3', self.__bam, l]
          else:
              cmd = [self.__samtools, 'view', '-c', '-F', '4', self.__bam, l]
           
          #print(' '.join(cmd))
          stdout = subprocess.Popen(cmd, stdout=subprocess.PIPE).stdout
          
          ret = int(stdout.readline().decode('utf-8').strip())
          
          stdout.close()
      
          return ret
docs: Iterate over the reads on a particular genome in the bam file.
          
          Parameters
          ----------
          l : str
              A location.