Added a few unit tests

Author: TheXDS

src/ServicePool.Tests/FlexPoolTests.cs

@@ -38,21 +38,38 @@ namespace TheXDS.ServicePool.Tests;
 public class FlexPoolTests
 {
     [Test]
-    public void Resolve_resolves_for_interfaces()
+    public void Resolve_with_FlexResolve_resolves_for_interfaces()
     {
         Pool pool = new(PoolConfig.FlexResolve);
         pool.Register<Test1>();
         Assert.That(pool.Resolve<ITest>(), Is.Not.Null);
     }
 
     [Test]
-    public void Resolve_resolves_for_base_class()
+    public void Resolve_with_FlexResolve_resolves_for_base_class()
     {
         Pool pool = new(PoolConfig.FlexResolve);
         pool.Register<Test3>();
         Assert.That(pool.Resolve<Test1>(), Is.Not.Null);
     }
 
+    [Test]
+    public void Resolve_with_FlexRegister_resolves_for_interfaces()
+    {
+        Pool pool = new(PoolConfig.FlexRegister);
+        pool.Register<Test1>();
+        Assert.That(pool.Resolve<ITest>(), Is.Not.Null);
+    }
+
+    [Test]
+    public void Resolve_with_FlexRegister_resolves_for_base_class()
+    {
+        Pool pool = new(PoolConfig.FlexRegister);
+        pool.Register<Test3>();
+        Assert.That(pool.Resolve<Test1>(), Is.Not.Null);
+    }
+
+
     [Test]
     public void Discover_searches_for_service()
     {

src/ServicePool/PoolConfig.cs

@@ -105,7 +105,9 @@ public readonly record struct PoolConfig
     /// them vary in the kind of services that could be registered.
     /// Using <see cref="FlexResolve"/> may allow multiple services that can
     /// expose the same service type to be registered, but only the first one
-    /// to match will be resolved.
+    /// to match will be resolved. This might be useful when "consuming"
+    /// services, where each one gets removed from the pool after being
+    /// resolved.
     /// </remarks>
     /// /// <seealso cref="FlexRegister"/>
     public static readonly PoolConfig FlexResolve = Default with {
@@ -124,7 +126,9 @@ public readonly record struct PoolConfig
     /// them vary in the kind of services that could be registered.
     /// Using <see cref="FlexRegister"/> will register the specified service
     /// type, as well as all of its base classes (except <see cref="object"/>)
-    /// and implemented interfaces.
+    /// and implemented interfaces. This will have the effect of disallowing
+    /// multiple services that can expose the same service type to be
+    /// registered.
     /// </remarks>
     /// <seealso cref="FlexResolve"/>
     public static readonly PoolConfig FlexRegister = Default with {