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 _restrict_to(self, ids):
      if self._s not in ids:
          return None
  
      return Trio(
          self._s,
          self._fam_id,
          self._pat_id if self._pat_id in ids else None,
          self._mat_id if self._mat_id in ids else None,
          self._is_female,
      )
  
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 13 for calling the Trio obj's underlying member method code with example usage: obj._restrict_to(ids) and returns: Trio, None