code: public static Node createAndCondition(Node left, Node right) {
  		checkNode(left, IN, AND, OR);
  		checkNode(right, IN, AND, OR);
  		return new Condition(Node.Type.AND, left, right);
  	}
docs: Create an "AND" condition.
  <p>
  @param left  left side of condition
  @param right right side of condition
  @return the "and" condition