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
docstr: ID of proband in trio, never missing.
  
  :rtype: str
docstr_tok: ["ID","of","proband","in","trio",",","never","missing",".",":","rtype",":","str"]
code: def s(self):
      """ID of proband in trio, never missing.
  
      :rtype: str
      """
  
      return self._s
  
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 6 for calling the Trio obj's underlying member method code with example usage: obj.s() and returns: self