HyperLogLog: approximate distinct value counting algoritm
'net.agkn:hll:1.3.0'
<dependency> <groupId>net.agkn</groupId> <artifactId>hll</artifactId> <version>1.3.0</version> </dependency>
<dependency org="net.agkn" name="hll" rev="1.3.0"/>
"net.agkn", "hll", "1.3.0"