This change improves the readability of the object-server's unit
tests by breaking down some long assertTrue statements into smaller
and much easier to read and more relevant assert statements.
For example:
assertTrue(a in resp.headers and
b in resp.headers and
c not in resp.headers)
Is equal to:
assertIn(a, resp.headers)
assertIn(b, resp.headers)
assertNotIn(c, resp.headers)
Change-Id: Iba746ecfb1a1dc541856b7a4c9d2f00d08e4ad51
b81f53b964