code: public static void exports(Xml root, CollisionFormula formula)
      {
          Check.notNull(root);
          Check.notNull(formula);
  
          final Xml node = root.createChild(NODE_FORMULA);
          node.writeString(ATT_NAME, formula.getName());
  
          CollisionRangeConfig.exports(node, formula.getRange());
          CollisionFunctionConfig.exports(node, formula.getFunction());
          CollisionConstraintConfig.exports(node, formula.getConstraint());
      }
docs: Export the current formula data to the formula node.
  
  @param root The root node (must not be <code>null</code>).
  @param formula The formula reference (must not be <code>null</code>).
  @throws LionEngineException If error on writing.