presto-main/src/main/java/io/prestosql/metadata/PolymorphicScalarFunction.java/PolymorphicScalarFunction/getBlockPositionCount
class PolymorphicScalarFunction:    private static int getBlockPositionCount(List<ArgumentProperty> argumentProperties)
    {
        return (int) argumentProperties.stream()
                .filter(argumentProperty -> argumentProperty.getNullConvention() == BLOCK_AND_POSITION)
                .count();
    }