Optionalcolumns?: string[]Optionalint64?: Int64PolicyINT64 / UINT64 columns: 'error' (default) | 'string' | 'number' — see Int64Policy.
OptionalnRows?: numberMax rows (= rowEnd - rowStart when rowStart set).
OptionalrowEnd?: numberExclusive end row.
OptionalrowStart?: numberInclusive start row (0-based).
Column subset by name.