Blank line is required after functions/methods.

All blank lines documented here:
https://github.com/paralect/robomongo/wiki/Robomongo-Coding-Style#wiki-blank-lines

Regardles of the rules, in the ExplorerDatabaseTreeItem.cpp file we have more than 21 methods with blank lines between them. Just follow The Golden Rule:
https://github.com/paralect/robomongo/wiki/Robomongo-Coding-Style#wiki-golden-rule