src/util.js
function _mapCopy(sourceRef, copyRef, rc) {
    return _instanceCopy(sourceRef, copyRef, rc, (map, val, key) => {
        map.set(key, _clone(val, rc));
    });
}
function _mapCopy(sourceRef, copyRef, rc) {
    return _instanceCopy(sourceRef, copyRef, rc, (map, val, key) => {
        map.set(key, _clone(val, rc));
    });
}
function _mapCopy ( sourceRef , copyRef , rc ) { return _instanceCopy ( sourceRef , copyRef , rc , ( map , val , key ) => { map . set ( key , _clone ( val , rc ) ) ; } ) ; }
Copies data from one map to another.

@param sourceRef A reference to the map source.
@param copyRef A reference to the map copy.
@param rc The current recurse and reference counter.
@returns {Map} The reference to the map copy.
Copies data from one map to another .