private static void AssertExpression(string content, string expected, int index = -1, PythonLanguageVersion version = PythonLanguageVersion.V35) { var buffer = new MockTextBuffer(content); if (index < 0) { index += content.Length + 1; } var span = new SnapshotSpan(buffer.CurrentSnapshot, index, 0); var actual = PythonTextBufferInfo.GetExpressionAtPoint(span, version, GetExpressionOptions.Hover); Assert.AreEqual(expected, actual?.GetText(), content); }