// Assume that the 'databases', 'logger', and 'eventloop' objects are initialized correctly.
// The connectionString has a wrong set of credentials, but forms a valid postgres connection string. 
do  {
            try databases.use(.postgres(url: connectionString), as: .psql)
            database = databases.database(.psql, logger: logger, on: databases.eventLoopGroup.next())
        } catch {
            throw error
        }

do {
            try databases.use(.postgres(url: connectionString), as: .psql)
            database = databases.database(.psql, logger: logger, on: databases.eventLoopGroup.next())
            // Note: Fluent does not throw error with wrong credentials.
            // Temporary workaround.
            guard let postgres = database as? PostgresDatabase else {
                //Throw some error. 
            }
            _ = try postgres.simpleQuery("SELECT 1").wait()
        }
        catch {
            throw error
        }