using System.Text; namespace TerminalGuiFluentTesting; class ThreadSafeStringWriter : StringWriter { private readonly object _lock; public ThreadSafeStringWriter (StringBuilder sb, object syncLock) : base (sb) { _lock = syncLock; } public override void Write (char value) { lock (_lock) { base.Write (value); } } public override void Write (string? value) { lock (_lock) { base.Write (value); } } // (override other Write* methods as needed) }