```
Undefined symbols for architecture x86_64:
"vtable for DB::IModel", referenced from:
DB::IModel::IModel() in Obfuscator.cpp.o
NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
ld: symbol(s) not found for architecture x86_64
clang-11: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.
```
The following files had some unused headers and caught my eyes, so
cleaning them up:
```bash
programs/obfuscator/Obfuscator.cpp
src/Databases/DatabaseAtomic.cpp
```
