Writer lifecycle (open/close/new_row_group/finish_row_group) and the type-generic shared helpers every write-specifics child (parquet_write_numeric/ _string/_temporal) reaches by host association: schema/column-info lookups, row-count and row-mask bookkeeping, output-name resolution, qc: integer-count text formatting (shared by numeric and string qc: reports), and the write_maml=.true. sidecar .maml.