/**
  * Apply the default value to the OutcomeVariable.
  * 
  * If no default value is described, and the cardinality is single and the baseType
  * is integer or float, the value of the variable becomes 0.
  * 
  */
 public function applyDefaultValue()
 {
     parent::applyDefaultValue();
     if (is_null($this->getDefaultValue()) === true && $this->getCardinality() === Cardinality::SINGLE) {
         if ($this->getBaseType() === BaseType::INTEGER) {
             $this->setValue(new Integer(0));
         } else {
             if ($this->getBaseType() === BaseType::FLOAT) {
                 $this->setValue(new Float(0.0));
             }
         }
     }
 }