bukkit-1.9/src/main/java/org/bukkit/enchantments/Enchantment.java
does not contain entries for the following:

/**

• Freezes any still water the player is walking on
  */
  public static final Enchantment FROST_WALKER = new EnchantmentWrapper(9);

and

/**

• Allows mending the item using XP orbs
  */
  public static final Enchantment MENDING = new EnchantmentWrapper(70);

so, basically those two enchantments are not supported by the API.

Also, looks like net.minecraft.server.Enchantments may not have correct enumerations...

public static final Enchantment j = a("frost_walker");

and
public static final Enchantment A = a("mending");

instead of

public static final Enchantment FROST_WALKER = a("frost_walker");

and

public static final Enchantment MENDING = a("mending");