ASM is an all purpose Java bytecode manipulation and analysis framework. It can be used to modify existing classes or dynamically 
generate classes, directly in binary form. This plugin helps you to easily see the bytecode of the current java file and you can 
also see the whole Java code that can be used to generate the same source code using ASM library that can be found in here:
http://asm.ow2.org/


You can use the plugin in 3 different ways:
1) Right click on the generated class file or somewhere inside the code editor and choose "ASM Bytecode Viewer"
2) In the "Code" menu, choose "ASM Bytecode Viewer"
3) Right click on the java file in the Project window and choose "ASM Bytecode Viewer"

You can find the setting inside Settings => Tools => "ASM Bytecode Viewer"