<BUG>import java.util.HashSet;import java.util.Set;import com.jgaap.generics.DistanceCalculationException;</BUG><CONTEXT>package com.jgaap.distances;<extra_id_0>import com.jgaap.generics.DistanceFunction;import com.jgaap.util.Event;</CONTEXT>
import com.google.common.collect.Sets;import com.jgaap.generics.DistanceCalculationException;