Adds the elements of a Level array to the current LevelCollection. 
 Adds the elements of a Level array to the current LevelCollection. 
public virtual int AddRange(Level[]);
 Adds the elements of another LevelCollection to the current LevelCollection. 
public virtual int AddRange(LevelCollection);
 Adds the elements of a Level collection to the current LevelCollection. 
public virtual int AddRange(ICollection);
LevelCollection Class | log4net.Core Namespace