question: public < T > Collection < T > load ( File dir , Class < T > type ) { Set < T > logImporters = new HashSet < > ( ) ; if ( ! dir . exists ( ) ) { return new ArrayList < > ( ) ; } File [ ] files = dir . listFiles ( null ) ; logImporters . addAll ( loadFromDir ( dir , type ) ) ; for ( File file : files ) { logImporters . addAll ( loadFromJar ( file , type ) ) ; } return logImporters ; }
target:  Load classes (interface implementation) from directory.