Assigns a single policy to a set of attribute definitions in
one request, replacing the need to call POST /definitions/{id}/policy once per attribute.

The operation is an upsert driven by readOnly. A definition carries either the read or the write marker of
a policy, never both, so each call replaces one with the other:

• readOnly=true grants read-only access: the read marker is added where missing and the write marker is
  removed where present.
• readOnly=false grants write access: the write marker is added where missing and the read marker is
  removed where present.

For more detailed information on how to work with access management in Bluestone PIM, refer to our help pages
Access management and Roles and policies
management.