[
  "group_head",
  "steam_knob",
  "coffee_spouts",
  "milk_reservoir",
  "portafilter",
  "bean_hopper",
  "steam_wand",
  "filter_basket",
  "drip_tray",
  "control_panel",
  "carafe",
  "coffee_machine",
  "power_switch",
  "water_reservoir"
]