Generate checks for keyword argument testing

		:param decorated_function: function decorator
		:param function_spec: function inspect information
		:param arg_specs: argument specification (same as arg_specs in :meth:`.Verifier.decorate`)

		:return: internal structure, that is used by :meth:`.Verifier._kwargs_checks_test`

def _kwargs_checks_gen(self, decorated_function, function_spec, arg_specs):
		""" Generate checks for keyword argument testing

		:param decorated_function: function decorator
		:param function_spec: function inspect information
		:param arg_specs: argument specification (same as arg_specs in :meth:`.Verifier.decorate`)

		:return: internal structure, that is used by :meth:`.Verifier._kwargs_checks_test`
		"""
		args_names = []
		args_names.extend(function_spec.args)
		if function_spec.varargs is not None:
			args_names.append(function_spec.args)

		args_check = {}

		for arg_name in arg_specs.keys():
			if arg_name not in args_names:
				args_check[arg_name] = self.check(
					arg_specs[arg_name], arg_name, decorated_function
				)
		return args_check