<PackageReference Include="Microsoft.Data.SqlClient" Version="7.1.0-preview3.26238.4" />

Microsoft.Data.SqlClient.ConnectionPool.BlockingPeriodErrorState

Encapsulates a connection pool's blocking-period error state: cached exception, exponential backoff timer, and synchronization. Kept as a separate class so the pool's connection-acquisition path remains focused on capacity/queue concerns and stays decoupled from the (independent) rate limiting policy.
namespace Microsoft.Data.SqlClient.ConnectionPool { internal sealed class BlockingPeriodErrorState : IDisposable { public void Dispose(); } }