An instance of UpsertContext
is passed to the upsertRows() method on your Datasource.Connection class. This class provides context
information about the upsert request to the implementor of upsertRows().
The Apex Connector Framework creates the contet for operations.
Context is comprised of parameters about the operations, which other methods can use. An
instance of the UpsertContext class packages these
parameters into an object that can be used when an upsertRows() operation is initiated.