code: def is_valid_feature_list(features):
      # Just test all the ways this could be
      return (
          type(features) is list
          and len(features) >= 1
          and all(type(t) is tuple and len(t) == 2 for t in features)
          and all(isinstance(n, str) for n, td in features)
          and all(
              datatypes._is_valid_datatype(td) for n, td in features
          )
      )
  
file_path: coremltools/coremltools/models/_feature_management.py
imports: import operator
  from collections import defaultdict
  from copy import copy
  from functools import reduce
  import numpy
  from .None import datatypes
label_desc: Use image node_id 2 for calling a global function with example usage: is_valid_feature_list(features) and returns: unknown