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Data Store

There is a newer version: 3.1.4

package com.jparams.store.index;

/**
 * Map a value to a single indexed key
 *
 * @param  key type
 * @param  value type
 */
@FunctionalInterface
public interface KeyMapper
{
    /**
     * Index value to key or return null to skip indexing
     *
     * @param value value to transform into a key
     * @return key
     */
    K map(V value);
}