Question: What is the language of the method used in the solution path "opendns_diagnosticapp\windows\OpenDnsDiagnostic.sln"?
SQL: SELECT T2.Lang FROM Solution AS T1 INNER JOIN Method AS T2 ON T1.Id = T2.SolutionId WHERE T1.Path = 'opendns_diagnosticappwindowsOpenDnsDiagnostic.sln'