generate(module, generateContext) {
		const type = generateContext.type;
		const generator = this.map[type];
		if (!generator) {
			throw new Error(`Generator.byType: no generator specified for ${type}`);
		}
		return generator.generate(module, generateContext);
	}
@param {NormalModule} module module for which the code should be generated
@param {GenerateContext} generateContext context for generate
@returns {Source | null} generated code