MimeKit.MimePart.WriteTo C# (CSharp) Method

		public override void WriteTo (FormatOptions options, Stream stream, bool contentOnly, CancellationToken cancellationToken = default (CancellationToken))
		{
			base.WriteTo (options, stream, contentOnly, cancellationToken);

			if (ContentObject == null)
				return;

			var cancellable = stream as ICancellableStream;

			if (ContentObject.Encoding != encoding) {
				if (encoding == ContentEncoding.UUEncode) {
					var begin = string.Format ("begin 0644 {0}", FileName ?? "unknown");
					var buffer = Encoding.UTF8.GetBytes (begin);

					if (cancellable != null) {
						cancellable.Write (buffer, 0, buffer.Length, cancellationToken);
						cancellable.Write (options.NewLineBytes, 0, options.NewLineBytes.Length, cancellationToken);
					} else {
						cancellationToken.ThrowIfCancellationRequested ();
						stream.Write (buffer, 0, buffer.Length);
						stream.Write (options.NewLineBytes, 0, options.NewLineBytes.Length);
					}
				}

				// transcode the content into the desired Content-Transfer-Encoding
				using (var filtered = new FilteredStream (stream)) {
					filtered.Add (EncoderFilter.Create (encoding));

					if (encoding != ContentEncoding.Binary)
						filtered.Add (options.CreateNewLineFilter (EnsureNewLine));

					ContentObject.DecodeTo (filtered, cancellationToken);
					filtered.Flush (cancellationToken);
				}

				if (encoding == ContentEncoding.UUEncode) {
					var buffer = Encoding.ASCII.GetBytes ("end");

					if (cancellable != null) {
						cancellable.Write (buffer, 0, buffer.Length, cancellationToken);
						cancellable.Write (options.NewLineBytes, 0, options.NewLineBytes.Length, cancellationToken);
					} else {
						cancellationToken.ThrowIfCancellationRequested ();
						stream.Write (buffer, 0, buffer.Length);
						stream.Write (options.NewLineBytes, 0, options.NewLineBytes.Length);
					}
				}
			} else if (encoding != ContentEncoding.Binary) {
				using (var filtered = new FilteredStream (stream)) {
					// Note: if we are writing the top-level MimePart, make sure it ends with a new-line so that
					// MimeMessage.WriteTo() *always* ends with a new-line.
					filtered.Add (options.CreateNewLineFilter (EnsureNewLine));
					ContentObject.WriteTo (filtered, cancellationToken);
					filtered.Flush (cancellationToken);
				}
			} else {
				ContentObject.WriteTo (stream, cancellationToken);
			}
		}

		public void TestArgumentExceptions ()
		{
			var part = new MimePart ();

			Assert.Throws<ArgumentNullException> (() => new MimePart ((string) null));
			Assert.Throws<ArgumentNullException> (() => new MimePart ((ContentType) null));
			Assert.Throws<ArgumentNullException> (() => new MimePart (null, "octet-stream"));
			Assert.Throws<ArgumentNullException> (() => new MimePart ("application", null));

			Assert.Throws<ArgumentOutOfRangeException> (() => part.ContentDuration = -1);
			Assert.Throws<ArgumentOutOfRangeException> (() => part.Prepare (EncodingConstraint.SevenBit, 1));

			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load ((Stream) null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load ((Stream) null, true));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load ((ParserOptions) null, Stream.Null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (ParserOptions.Default, (Stream) null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (null, Stream.Null, true));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (ParserOptions.Default, (Stream) null, true));

			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load ((ContentType) null, Stream.Null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (new ContentType ("application", "octet-stream"), null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (null, new ContentType ("application", "octet-stream"), Stream.Null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (ParserOptions.Default, null, Stream.Null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (ParserOptions.Default, new ContentType ("application", "octet-stream"), null));

			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load ((string) null));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (null, "fileName"));
			Assert.Throws<ArgumentNullException> (() => MimeEntity.Load (ParserOptions.Default, (string) null));

			Assert.Throws<ArgumentNullException> (() => part.Accept (null));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo ((string) null));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo ((Stream) null));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo ((string) null, false));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo ((Stream) null, false));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (null, Stream.Null));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (FormatOptions.Default, (Stream) null));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (null, "fileName"));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (FormatOptions.Default, (string) null));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (null, Stream.Null, false));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (FormatOptions.Default, (Stream) null, false));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (null, "fileName", false));
			Assert.Throws<ArgumentNullException> (() => part.WriteTo (FormatOptions.Default, (string) null, false));
		}