parse(token, context, chain) {
                const state = this;

                return Twig.expression.parseAsync.call(state, token.stack, context)
                    .then(filePath => {
                        // Create a new state instead of using the current state
                        // any defined blocks will be created in isolation

                        const useTemplate = state.template.importFile(filePath);

                        const useState = new Twig.ParseState(useTemplate);
                        return useState.parseAsync(useTemplate.tokens)
                            .then(() => {
                                state.template.blocks.imported = {
                                    ...state.template.blocks.imported,
                                    ...useState.getBlocks()
                                };
                            });
                    })
                    .then(() => {
                        return {
                            chain,
                            output: ''
                        };
                    });
            }
Block logic tokens.

 Format: {% use "template.twig" %}