How to get the object info from variable?

Some time ago I made this plugin https://plugins.jetbrains.com/plugin/12590-php-code-generator-/
(https://github.com/KristijanKanalas/PHPCodeGeneratorPlus). And I went the round about way of getting the information about a variable. Particularly I am not sure how to correctly get the name of the class the variable was instantiated as. I can't seem to find much about this topic on the official docs. Does anyone know how to do this?