@@ -0,0 +1,383 @@
+package ru.dyatel.tsuschedule.parsing.util;%0A%0Aimport java.util.HashSet;%0Aimport java.util.Set;%0A%0Apublic abstract class KeyExtractor%3CIT, KT%3E %7B%0A%0A    public Set%3CKT%3E extract(Set%3CIT%3E set) %7B%0A        Set%3CKT%3E result = new HashSet%3CKT%3E();%0A        for (IT item : set) %7B%0A            result.add(getKey(item));%0A        %7D%0A        return result;%0A    %7D%0A%0A    protected abstract KT getKey(IT element);%0A%0A%7D%0A

Add Set KeyExtractor util class