docs: def get_column(self, chrom, position,
                   missing_seqs=MissingSequenceHandler.TREAT_AS_ALL_GAPS,
                   species=None):
      """Get the alignment column at the specified chromosome and position."""
      blocks = self.get_blocks(chrom, position, position + 1)
      if len(blocks) == 0:
        raise NoSuchAlignmentColumnError("Request for column on chrom " +
                                         chrom + " at position " +
                                         str(position) + " not possible; " +
                                         "genome alignment not defined at " +
                                         "that locus.")
      if len(blocks) > 1:
        raise NoUniqueColumnError("Request for column on chrom " + chrom +
                                  " at position " + str(position) + "not " +
                                  "possible; ambiguous alignment of that locus.")
  
      return blocks[0].get_column_absolute(position, missing_seqs, species)