class_docstr: Class containing information about nuclear family relatedness and sex.
  
  :param str s: Sample ID of proband.
  
  :param fam_id: Family ID.
  :type fam_id: str or None
  
  :param pat_id: Sample ID of father.
  :type pat_id: str or None
  
  :param mat_id: Sample ID of mother.
  :type mat_id: str or None
  
  :param is_female: Sex of proband.
  :type is_female: bool or None
code: def _sex_as_numeric_string(self):
      if self._is_female is None:
          return "0"
      return "2" if self.is_female else "1"
  
imports: import re
  from collections import Counter
  from hail.typecheck import typecheck_method, nullable, sequenceof
  from hail.utils.java import Env, FatalError, warning
label_desc: Use image node_id 14 for calling the Trio obj's underlying member method code with example usage: obj._sex_as_numeric_string() and returns: unknown, str