viewability property
The read access of a volume.
Possible values are PARTIAL, ALL_PAGES, NO_PAGES or UNKNOWN. This value depends on the country listed above. A value of PARTIAL means that the publisher has allowed some portion of the volume to be viewed publicly, without purchase. This can apply to eBooks as well as non-eBooks. Public domain books will always have a value of ALL_PAGES.
Implementation
core.String? viewability;