From c66d0c746e2d76a2f92b01c7d613f07502b6d6fc Mon Sep 17 00:00:00 2001
From: YoshiRulz <OSSYoshiRulz@gmail.com>
Date: Wed, 25 Jan 2023 02:04:10 +1000
Subject: [PATCH] Document `IMemoryDomains` invariants

---
 .../Interfaces/Services/IMemoryDomains.cs                   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/BizHawk.Emulation.Common/Interfaces/Services/IMemoryDomains.cs b/src/BizHawk.Emulation.Common/Interfaces/Services/IMemoryDomains.cs
index 85b4629363..aa96394955 100644
--- a/src/BizHawk.Emulation.Common/Interfaces/Services/IMemoryDomains.cs
+++ b/src/BizHawk.Emulation.Common/Interfaces/Services/IMemoryDomains.cs
@@ -17,10 +17,16 @@ namespace BizHawk.Emulation.Common
 	{
 		MemoryDomain? this[string name] { get; }
 
+		/// <remarks>implementation note: must also be in the collection</remarks>
 		MemoryDomain MainMemory { get; }
 
 		bool HasSystemBus { get; }
 
+		/// <remarks>
+		/// if <see cref="HasSystemBus"/> is <see langword="false"/>, the getter behaviour is undefined
+		/// (it may return <see cref="MainMemory"/> or another domain)<br/>
+		/// implementation note: must also be in the collection
+		/// </remarks>
 		MemoryDomain SystemBus { get; }
 
 		bool Has(string name);