class_docstr: A hook to check the sanity of configured features
  -   before it called by the abstract class '_Feature'
      
code: def test_implies(
      self, error_msg, search_in, feature_name, feature_dict
  ):
      if feature_dict.get("disabled") is not None:
          return
      implies = feature_dict.get("implies", "")
      if not implies:
          return
      if isinstance(implies, str):
          implies = implies.split()
  
      if feature_name in implies:
          raise AssertionError(error_msg + "feature implies itself")
  
      for impl in implies:
          impl_dict = search_in.get(impl)
          if impl_dict is not None:
              if "disable" in impl_dict:
                  raise AssertionError(
                      error_msg + "implies disabled feature '%s'" % impl
                  )
              continue
          raise AssertionError(
              error_msg + "implies non-exist feature '%s'" % impl
          )
  
imports: import unittest
  from os import sys, path
label_desc: Use image node_id 5 for calling the _TestConfFeatures obj's underlying member method code with example usage: obj.test_implies(error_msg, search_in, feature_name, feature_dict) without return types