presto-main/src/main/java/io/prestosql/type/TypeUtils.java/TypeUtils/positionEqualsPosition
class TypeUtils:    public static boolean positionEqualsPosition(Type type, Block leftBlock, int leftPosition, Block rightBlock, int rightPosition)
    {
        boolean leftIsNull = leftBlock.isNull(leftPosition);
        boolean rightIsNull = rightBlock.isNull(rightPosition);
        if (leftIsNull || rightIsNull) {
            return leftIsNull && rightIsNull;
        }
        return type.equalTo(leftBlock, leftPosition, rightBlock, rightPosition);
    }