/// <summary>
/// Assert that a file exists and whose
/// <see cref="Org.Apache.Hadoop.FS.FileStatus"/>
/// entry
/// declares that this is a file and not a symlink or directory.
/// </summary>
/// <param name="filename">name of the file</param>
/// <exception cref="System.IO.IOException">IO problems during file operations</exception>
protected internal virtual void AssertIsFile(Org.Apache.Hadoop.FS.Path filename)
{
ContractTestUtils.AssertIsFile(fileSystem, filename);
}