def _call_schema(self, function: ValidateCallSupportedTypes) -> core_schema.CallSchema:
        """Generate schema for a Callable.

        TODO support functional validators once we support them in Config
        """
        arguments_schema = self._arguments_schema(function)

        return_schema: core_schema.CoreSchema | None = None
        config_wrapper = self._config_wrapper
        if config_wrapper.validate_return:
            sig = signature(function)
            return_hint = sig.return_annotation
            if return_hint is not sig.empty:
                globalns, localns = self._types_namespace
                type_hints = _typing_extra.get_function_type_hints(
                    function, globalns=globalns, localns=localns, include_keys={'return'}
                )
                return_schema = self.generate_schema(type_hints['return'])

        return core_schema.call_schema(
            arguments_schema,
            function,
            return_schema=return_schema,
        )
Generate schema for a Callable.

        TODO support functional validators once we support them in Config
        
pydantic/_internal/_generate_schema.py