def shift(severity, shift=0, &block)
      severity = ZTK::Logger.const_get(severity.to_s.upcase)
      add(severity, nil, nil, shift, &block)
    end
def shift(severity, shift=0, &block)
      severity = ZTK::Logger.const_get(severity.to_s.upcase)
      add(severity, nil, nil, shift, &block)
    end
Specialized logging.  Logs messages in the same format, except has the
 option to shift the caller_at position to exposed the proper calling
 method.

 Very useful in situations of class inheritence, for example, where you
 might have logging statements in a base class, which are inherited by
 another class.  When calling the base class method via the inherited class
 the log messages will indicate the base class as the caller.  While this
 is technically true it is not always what we want to see in the logs
 because it is ambigious and does not show us where the call truly
 originated from.