/*.................................................................................................................*/
 public CharacterDistribution getCharacter(Taxa taxa, int ic) {
   CharacterObedSource oldSource = characterSourceTask;
   CharacterDistribution matrix = characterSourceTask.getCharacter(taxa, ic);
   if (oldSource
       == characterSourceTask) // i.e., old source hasn't quit and been replaced during above call!
   return matrix;
   return characterSourceTask.getCharacter(taxa, ic);
 }