code: public double getNumber(String nameOfField, double defaultValue) {
  		Double value = ((Double)numericData.get(nameOfField));
  		
  		if (value == null) {
  			return defaultValue;
  		}
  		
  		return value.doubleValue();
  	}
docs: Get number stored at given location
  
  @param nameOfField The name of the number to retrieve
  @param defaultValue The value to return if the specified value hasn't been set
  @return The number saved at this location