public void ExtractLine()
{
var text =
"0123\n" +
"\n" +
"0";
var doc = new TextDocument(text, TestCommon.UriMock);
Assert.AreEqual("0123\n", doc.ExtractLine(0));
Assert.AreEqual("0123\n", doc.ExtractLine(1));
Assert.AreEqual("0123\n", doc.ExtractLine(4));
Assert.AreEqual("\n", doc.ExtractLine(5));
Assert.AreEqual("0", doc.ExtractLine(6));
}