services.AddOptions<SysConfig>()
    .Configure<IConfiguration>((options, configuration) => configuration.Bind(SysConfig.SectionName, options))
    .Validate(options => options.Port is not default(int), $"{nameof(SysConfig.Port)} is not defined!")

services.AddOptions<SysConfig>()
    .Configure<IConfiguration>((options, configuration) => configuration.Bind(SysConfig.SectionName, options))
    .Validate(options => options.Port is not default(int), $"{nameof(SysConfig.Port)} is not defined!")

.Configure<IConfiguration>((options, configuration) =>
{
    IConfigurationSection sysSection = configuration.GetRequiredSection("Sys");
    if (!sysSection.Exists()) throw new Exception("Missing section \"Sys\" in configuration!");

    var portAsString = sysSection.GetValue<string>("Port");

    options.Port = int.Parse(portAsString!);
})

.Configure<IConfiguration>((options, configuration) =>
{
    IConfigurationSection sysSection = configuration.GetRequiredSection("Sys");
    if (!sysSection.Exists()) throw new Exception("Missing section \"Sys\" in configuration!");

    var portAsString = sysSection.GetValue<string>("Port");

    options.Port = int.Parse(portAsString!);
})

Main 
{
    DownstreamFrequency 130000000;
    UpstreamChannelId 123;
    NetworkAccess 1;
    ClassOfService
    {
        ClassID 5;
        MaxRateDown 512000;
        MaxRateUp 64000;
        PriorityUp 3;
        GuaranteedUp 32000;
        MaxBurstUp 54314;
        PrivacyEnable 1;
    }
    MaxCPE 13;
    SwUpgradeServer 10.1.1.1;
    /* CmMic e241803a16fa62269f90d6e1619a59d3; */
    /* CmtsMic 41141948116bcc38f6a20ec485fcd0f2; */
    /*EndOfDataMkr*/
}

Main 
{
    DownstreamFrequency 130000000;
    UpstreamChannelId 123;
    NetworkAccess 1;
    ClassOfService
    {
        ClassID 5;
        MaxRateDown 512000;
        MaxRateUp 64000;
        PriorityUp 3;
        GuaranteedUp 32000;
        MaxBurstUp 54314;
        PrivacyEnable 1;
    }
    MaxCPE 13;
    SwUpgradeServer 10.1.1.1;
    /* CmMic e241803a16fa62269f90d6e1619a59d3; */
    /* CmtsMic 41141948116bcc38f6a20ec485fcd0f2; */
    /*EndOfDataMkr*/
}

CoreApp.Customers.dll
  - ICustomersService.cs
CoreApp.Products.dll
  - IProductsService.cs

CoreApp.Customers.dll
  - ICustomersService.cs
CoreApp.Products.dll
  - IProductsService.cs

Internal.CoreApp
  Customers
  Products

Internal.CoreApp
  Customers
  Products

private readonly ConcurrentDictionary<string, SemaphoreSlim> entityLocks = new();

SemaphoreSlim semaphore = entityLocks.GetOrAdd(entity.Id, new SemaphoreSlim(1));
        await semaphore.WaitAsync(TimeSpan.FromMilliseconds(config.LockTimeoutMilliseconds)).ConfigureAwait(false);

try 
{
  // do stuff
} 
finally
{
  semaphore.Release();
  entityLocks.TryRemove(entity.Id, out _);
}

private readonly ConcurrentDictionary<string, SemaphoreSlim> entityLocks = new();

SemaphoreSlim semaphore = entityLocks.GetOrAdd(entity.Id, new SemaphoreSlim(1));
        await semaphore.WaitAsync(TimeSpan.FromMilliseconds(config.LockTimeoutMilliseconds)).ConfigureAwait(false);

try 
{
  // do stuff
} 
finally
{
  semaphore.Release();
  entityLocks.TryRemove(entity.Id, out _);
}

public IEnumerable<int> A()
{
    for (int i = 0; i <= 10; i += 2)
        yield return i;
}



public IEnumerable<int> B()
{
    var ints = new List<int>();
    for (int i = 0; i <= 10; i += 2) 
        ints.Add(i);

    return ints;
}

public IEnumerable<int> A()
{
    for (int i = 0; i <= 10; i += 2)
        yield return i;
}



public IEnumerable<int> B()
{
    var ints = new List<int>();
    for (int i = 0; i <= 10; i += 2) 
        ints.Add(i);

    return ints;
}

InternalDbSet<MyEntity> invocation failed with mock behavior Strict.
All invocations on the mock must have a corresponding setup.

InternalDbSet<MyEntity> invocation failed with mock behavior Strict.
All invocations on the mock must have a corresponding setup.

Event
  int EventTypeId
  int CustomerId

Event
  int EventTypeId
  int CustomerId

from event in events
group event by event.CustomerId
into customerEvents
where customerEvents.All(event => event.EventTypeId != 2)
select customerEvents

from event in events
group event by event.CustomerId
into customerEvents
where customerEvents.All(event => event.EventTypeId != 2)
select customerEvents

Task.Run(async () => await myDbContext.MyDbSet.Join() // etc

Task.Run(async () => await myDbContext.MyDbSet.Join() // etc

public readonly struct Outcome<T> {
  private readonly T value;
  private readonly string errorMessage
  public readonly bool IsSuccess

  public static Outcome<T> Of(Func<T> function)
  {
      if (function == null)
          throw new ArgumentNullException(nameof(function));
  
      try
      {
          var value = function();
  
          if (value == null)
              return value == null ? Error("Value cannot be null!") : Success(value);
              // throw new ValueIsNullException("Value cannot be null!");
  
          return Success(value);
      }
      catch (Exception exception)
      {
          return Error(exception);
      }
  }

public readonly struct Outcome<T> {
  private readonly T value;
  private readonly string errorMessage
  public readonly bool IsSuccess

  public static Outcome<T> Of(Func<T> function)
  {
      if (function == null)
          throw new ArgumentNullException(nameof(function));
  
      try
      {
          var value = function();
  
          if (value == null)
              return value == null ? Error("Value cannot be null!") : Success(value);
              // throw new ValueIsNullException("Value cannot be null!");
  
          return Success(value);
      }
      catch (Exception exception)
      {
          return Error(exception);
      }
  }

public static void Debug(this ILogger logger,
                         string logMessage,
                         [CallerMemberName] string memberName = "",
                         params object[] propertyValues)
{
    using (LogContext.PushProperty("MethodName", memberName)) 
        logger?.Debug(logMessage, propertyValues.ToArray());
}

public static void Debug(this ILogger logger,
                         string logMessage,
                         [CallerMemberName] string memberName = "",
                         params object[] propertyValues)
{
    using (LogContext.PushProperty("MethodName", memberName)) 
        logger?.Debug(logMessage, propertyValues.ToArray());
}