hollow/src/main/java/com/netflix/hollow/core/read/engine/SetMapKeyHasher.java
public static int hash(Object key[], FieldType fieldType[]) {
        int hash = 0;

        for (int i = 0; i < key.length; i++) {
            hash *= 31;
            hash ^= hash(key[i], fieldType[i]);
        }

        return hash;
    }
public static int hash(Object key[], FieldType fieldType[]) {
        int hash = 0;

        for (int i = 0; i < key.length; i++) {
            hash *= 31;
            hash ^= hash(key[i], fieldType[i]);
        }

        return hash;
    }
Hash a key

@param key the key
@param fieldType the respective FieldTypes of each key.
@return the hash code