code: def _check_contigs_to_use(self, ref_dict):
          '''Checks that the set of contigs to use are all in the reference
          fasta lengths dict made by self._get_ref_lengths()'''
          if self.contigs_to_use is None:
              return True
  
          for contig in self.contigs_to_use:
              if contig not in ref_dict:
                  raise Error('Requested to use contig "' + contig + '", but not found in input BAM file "' + self.bam + '"')
  
          return Truf _check_contigs_to_use(self, ref_dict):
          '''Checks that the set of contigs to use are all in the reference
          fasta lengths dict made by self._get_ref_lengths()'''
          if self.contigs_to_use is None:
              return True
  
          for contig in self.contigs_to_use:
              if contig not in ref_dict:
                  raise Error('Requested to use contig "' + contig + '", but not found in input BAM file "' + self.bam + '"')
  
          return True
docs: Checks that the set of contigs to use are all in the reference
          fasta lengths dict made by self._get_ref_lengths()