<has_function_call>I am creating a PvE macro for a Death Knight Blood for use during difficult content.

Here's the explanation for the macro you requested:

- **#showtooltip**: This command shows the tooltip of the spell that will be cast, which in this case is Death Strike by default.

- **/cast [nomod] Death Strike**: This line casts Death Strike when no modifier key is pressed. Death Strike is your primary healing and damage ability, healing you based on damage dealt to enemies.

- **/cast [mod:shift] Blood Boil**: When you press Shift, this macro will cast Blood Boil instead, which is useful for AoE damage and applying diseases to multiple targets.

- **/use [nomod] 13**: This uses your first trinket (slot 13) if no modifier key is pressed, providing an additional burst or utility effect during combat.

- **/use [nomod] 14**: Similarly, this uses your second trinket (slot 14) without a modifier key, enhancing your performance or survival.

**When to use this macro**: This macro is designed for PvE scenarios where you need to manage your health with Death Strike, apply diseases with Blood Boil, and utilize your trinkets for additional benefits. It's particularly useful in dungeon or raid settings where you need to react quickly to changing situations.

**Customization Tips**:

- You might want to replace Blood Boil with another ability like Marrowrend if you find yourself needing more bone shield stacks in certain fights.

- If you have specific trinkets with cooldowns you want