stsBP-class: Class "stsBP" -- a class inheriting from class sts which
  allows the user to store the results of back-projecting or nowcasting
  surveillance time series
Description
A class inheriting from class sts, but with additional slots
  to store the result and associated confidence intervals from back
  projection of a sts object.encoding
latin1Methods
The methods are the same as for "sts".  
- signature(from = "sts", to = "stsBP")
{
      Convert an object of classsts to class stsBP.
    }