static void NVIC_Configuration(void){NVIC_InitTypeDef NVIC_InitStructure;NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);NVIC_InitStructure.NVIC_IRQChannel = KEY1_INT_EXTI_IRQ;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_Init(&NVIC_InitStructure);NVIC_InitStructure.NVIC_IRQChannel = KEY2_INT_EXTI_IRQ;NVIC_Init(&NVIC_InitStructure);}以上是SDK中断实验的中断配置函数NVIC_Configuration()的内容，请写出每行代码的功能？