Aggregate use of Whitebox in file stream tests

Description

Instead of calling Whitebox all over FileOutStreamTest and FileInStreamTest, we should aggregate our use of Whitebox in a PrivateAccess classes. This reduces the number places which need to be changed if we ever change the name of methods or fields accessed reflectively. See BlockMasterTest for an example of this.

Environment

None

Assignee

Unassigned

Reporter

Andrew Audibert

Labels

Affects versions

Priority

Minor