presto-main/src/main/java/io/prestosql/operator/scalar/MapDistinctFromOperator.java/MapDistinctFromOperator/isDistinctFrom
class MapDistinctFromOperator:    @TypeParameter("K")
    @TypeParameter("V")
    @SqlType(StandardTypes.BOOLEAN)
    public static boolean isDistinctFrom(
            @OperatorDependency(operator = IS_DISTINCT_FROM, argumentTypes = {"V", "V"}, convention = @Convention(arguments = {BLOCK_POSITION, BLOCK_POSITION}, result = FAIL_ON_NULL))
                    MethodHandle valueDistinctFromFunction,
            @TypeParameter("map(K, V)") Type mapType,
            @BlockPosition @SqlType(value = "map(K,V)", nativeContainerType = Block.class) Block left,
            @BlockIndex int leftPosition,
            @BlockPosition @SqlType(value = "map(K,V)", nativeContainerType = Block.class) Block right,
            @BlockIndex int rightPosition)
    {
        return isDistinctFrom(
                valueDistinctFromFunction,
                mapType,
                (Block) mapType.getObject(left, leftPosition),
                left.isNull(leftPosition),
                (Block) mapType.getObject(right, rightPosition),
                right.isNull(rightPosition));
    }