How to use appeng.api.definitions

@Override
public boolean allowInsert( IItemHandler inv, int slot, ItemStack stack )
{
  return this.definition.isSameAs( stack );
}

@Override
public ItemStack getIconItemStack()
{
  final IDefinitions definitions = AEApi.instance().definitions();
  final IBlocks blocks = definitions.blocks();
  final IItems items = definitions.items();
  final IMaterials materials = definitions.materials();
  return this.findFirst( blocks.controller(), blocks.chest(), blocks.cellWorkbench(), blocks.fluixBlock(), items.cell1k(), items.networkTool(),
      materials.fluixCrystal(), materials.certusQuartzCrystal(), materials.skyDust() );
}

  public static boolean isRecipePrioritized( final ItemStack what )
  {
    final IMaterials materials = AEApi.instance().definitions().materials();

    boolean isPurified = materials.purifiedCertusQuartzCrystal().isSameAs( what );
    isPurified |= materials.purifiedFluixCrystal().isSameAs( what );
    isPurified |= materials.purifiedNetherQuartzCrystal().isSameAs( what );

    return isPurified;
  }
}

private void registerFacadeRecipe( IDefinitions definitions, IModRegistry registry )
{
  Optional<Item> itemFacade = definitions.items().facade().maybeItem();
  Optional<ItemStack> cableAnchor = definitions.parts().cableAnchor().maybeStack( 1 );
  if( itemFacade.isPresent() && cableAnchor.isPresent() )
  {
    registry.addRecipeRegistryPlugin( new FacadeRegistryPlugin( (ItemFacade) itemFacade.get(), cableAnchor.get() ) );
  }
}

@Override
public void drawBG( final int offsetX, final int offsetY, final int mouseX, final int mouseY )
{
  super.drawBG( offsetX, offsetY, mouseX, mouseY );
  final IDefinitions definitions = AEApi.instance().definitions();
  definitions.items().cell1k().maybeStack( 1 ).ifPresent( cell1kStack -> this.drawItem( offsetX + 66 - 8, offsetY + 17, cell1kStack ) );
  definitions.blocks().drive().maybeStack( 1 ).ifPresent( driveStack -> this.drawItem( offsetX + 94 + 8, offsetY + 17, driveStack ) );
}

private boolean isPattern( final ItemStack output )
{
  if( output.isEmpty() )
  {
    return false;
  }
  final IDefinitions definitions = AEApi.instance().definitions();
  boolean isPattern = definitions.items().encodedPattern().isSameAs( output );
  isPattern |= definitions.materials().blankPattern().isSameAs( output );
  return isPattern;
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().parts().iface().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public boolean canHandle( final ItemStack is )
{
  return AEApi.instance().definitions().items().wirelessTerminal().isSameAs( is );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().parts().storageBus().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().blocks().iface().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().parts().formationPlane().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().parts().fluidStorageBus().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().parts().fluidIface().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().parts().fluidFormationnPlane().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public boolean allowInsert( IItemHandler inv, final int i, final ItemStack itemstack )
{
  final IItemDefinition cert = AEApi.instance().definitions().materials().certusQuartzCrystal();
  return Platform.isChargeable( itemstack ) || cert.isSameAs( itemstack );
}

@Override
public void registerItemSubtypes( ISubtypeRegistry subtypeRegistry )
{
  final Optional<Item> maybeFacade = AEApi.instance().definitions().items().facade().maybeItem();
  maybeFacade.ifPresent( subtypeRegistry::useNbtForSubtypes );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().blocks().fluidIface().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().blocks().chest().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getItemStackRepresentation()
{
  return AEApi.instance().definitions().blocks().drive().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}

@Override
public ItemStack getContainerItem( final ItemStack itemStack )
{
  return AEApi.instance().definitions().blocks().craftingUnit().maybeStack( 1 ).orElse( ItemStack.EMPTY );
}