class_docstr: A tree choice chooses one path to a leaf in a tree
  
  Trees are represented as collections of two-tuples. The first element is
  the name of the node and the second is either None if a leaf or
  a sub-collection of two-tuples. For instance:
  (("Foo", (("1", None),("2", None))), ("Bar", None))
  is a tree for selecting ("Foo", "1"), ("Foo", "2") or ("Bar",).
  
  A good UI choice would be a hierarchical menu.
code: def default_fn_is_leaf(node):
      return node[1] is None or len(node[1]) == 0
  
file_path: CellProfiler/src/subpackages/core/cellprofiler_core/setting/_tree_choice.py
imports: import re
  from ._setting import Setting
  from ._validation_error import ValidationError
label_desc: Use image node_id 2 for calling the TreeChoice obj's underlying member method code with example usage: obj.default_fn_is_leaf(node) and returns: unknown