public EfModule(string sqlServerConnectionString)
{
var builder = new DbContextOptionsBuilder <TrackerDbContext>();
builder.UseSqlServer(sqlServerConnectionString, options => { options.EnableRetryOnFailure(); });
builder.ConfigureWarnings(w => w.Throw(RelationalEventId.QueryPossibleUnintendedUseOfEqualsWarning));
this.options = builder.Options;
}