change extension methods to be able to apply to the TextReader/TextWriter

Author: smdn

tests/Smdn.Net.MuninNode/Smdn.Net.MuninNode/StreamReaderWriterExtensions.cs renamed to tests/Smdn.Net.MuninNode/Smdn.Net.MuninNode/TextReaderWriterExtensions.cs

@@ -11,21 +11,21 @@
 
 namespace Smdn.Net.MuninNode;
 
-internal static class StreamReaderWriterExtensions {
+internal static class TextReaderWriterExtensions {
 #if !SYSTEM_IO_TEXTREADER_READLINEASYNC_CANCELLATIONTOKEN
-  public static async Task<string?> ReadLineAsync(this StreamReader reader, CancellationToken cancellationToken)
+  public static async Task<string?> ReadLineAsync(this TextReader reader, CancellationToken cancellationToken)
     => await reader.ReadLineAsync().WaitAsync(cancellationToken).ConfigureAwait(false);
 #endif
 
-  public static async Task WriteLineAsync(this StreamWriter writer, string value, CancellationToken cancellationToken)
+  public static async Task WriteLineAsync(this TextWriter writer, string value, CancellationToken cancellationToken)
 #if SYSTEM_IO_TEXTWRITER_WRITELINEASYNC_CANCELLATIONTOKEN
     => await writer.WriteLineAsync(value.AsMemory(), cancellationToken).ConfigureAwait(false);
 #else
     => await writer.WriteLineAsync(value.AsMemory()).WaitAsync(cancellationToken).ConfigureAwait(false);
 #endif
 
 #if !SYSTEM_IO_TEXTWRITER_FLUSHASYNC_CANCELLATIONTOKEN
-  public static async Task FlushAsync(this StreamWriter writer, CancellationToken cancellationToken)
+  public static async Task FlushAsync(this TextWriter writer, CancellationToken cancellationToken)
     => await writer.FlushAsync().WaitAsync(cancellationToken).ConfigureAwait(false);
 #endif
 }