TestDefaultStatsService done.
initial commit TestDefaultOAuth2ProviderTokenService.
removed testing builder inner class from DefaultOAuth2ProviderTokenService. Also, added more unit tests.
more unit tests for TestDefaultOAuth2ProviderTokenService.
initial commit for TestDefaultSystemScopeService.
TestDefaultSystemScopeService unit tests done.
init commit TestPlainAuthRequestUrlBuilder.
TestPlainAuthRequestUrlBuilder done.
TestThirdPartyIssuerService done.