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 __init__(self, trios):
      self._trios = tuple(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 1 to create a new Pedigree object from inherited base classes: object with example: obj = Pedigree(trios)