eParaksts Java Libraries uses The Apache Log4j 2 API for logging.

The Log4j 2 API is a logging facade that may be used with the Log4j implementation, but may also be used in front of other logging implementations.
https://logging.apache.org/log4j/2.x/manual/index.html

log4j-core-*.jar
The Apache Log4j Core Implementation
https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core

log4j-slf4j2-impl-*.jar
The Apache Log4j SLF4J 2.0 API binding to Log4j 2 Core
https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-slf4j2-impl
