1.8-1.12 version support

[unldenis]

As you may have noticed versions 1.8 -1.12 are not supported, why?
Because from 1.13 it is possible to set the pose of the npc to SLEEPING.
In previous versions instead you have to use a PacketPlayOutBed, which causes problems.

Using this code I can make him sleep, however I cannot make the bed invisible.

Location location=...
player.sendBlockChange(location, Material.valueOf("BED_BLOCK"), (byte) 0);
player.sendBlockChange(location.add(0, 0, 1), Material.valueOf("BED_BLOCK"), (byte) 2);

PacketContainer packet = new PacketContainer(PacketType.Play.Server.BED);
BlockPosition blockPos = new BlockPosition(location.getBlock().getX(), location.getBlock().getY(), location.getBlock().getZ());
packet.getIntegers().write(0, id);
packet.getBlockPositionModifier().write(0, blockPos);

Preview Result

As you can see in the image the npc skin is not visible, why? because in this version(1.8.8) a ClassNotFoundException is thrown referring to the Guava MultiMap.
The solution is * not * to import the entire library as it weighs 3MB.

[Happy-FZM]

I tested this code and it works (1.12.2).
I found that it only works when use ProtocolLibrary.getProtocolManager().sendServerPacket().
If you use ProtocolLibrary.getProtocolManager().broadcastServerPacket() it not works.

  public static PacketContainer PLAYER_SLEEPING(Location loc, int entityId) {
      PacketContainer packet = ProtocolLibrary.getProtocolManager().createPacket(PacketType.Play.Server.BED);
      packet.getIntegers().write(0, entityId);
      packet.getBlockPositionModifier().write(0, new BlockPosition(loc.getBlockX(), loc.getBlockY(), loc.getBlockZ()));
      return packet;
  }

Done #2!