pub fn merge_dtypes_many<I: IntoIterator<Item = D> + Clone, D: AsRef<DataType>>(
into_iter: I,
) -> PolarsResult<DataType>pub fn merge_dtypes_many<I: IntoIterator<Item = D> + Clone, D: AsRef<DataType>>(
into_iter: I,
) -> PolarsResult<DataType>