class_docstr: Class containing a list of trios, with extra functionality.
  
  :param trios: list of trio objects to include in pedigree
  :type trios: list of :class:`.Trio`
code: def __hash__(self):
      return hash(self._trios)
  
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 3 for calling the Pedigree obj's underlying member method code with example usage: obj.__hash__() and returns: hash