Xtrace : iprint = awt activates method trace and set the output to stderr with indentations .
iprint=mt激活方法跟踪并将输出发送到stderr，进行缩进。
Xtrace : iprint = awt traces all of the JVM internal AWT trace points to stderr , with indentations on entry and exit .
iprint=awt将所有JVM内部AWT跟踪点记录到stderr，在进入和退出时进行缩进。
iprint