rack 0 is the first item which contains all racks

[
[
{'building': 'FRA2 (FRA11, EU9)', 'number_between_us': True, 'orientation': 'left', 'tags': [], 'numbering_start_from_bottom': 'yes', 'col_size': 1.0, 'rack_middle_option': 'Start at', 'asset_no': '', 'name': 'rack1', 'available_u': 41.0, 'rack_url': '/api/1.0/racks/1/', 'room': 'Room 007', 'start_col': 3.0, 'row_size': 1.0, 'start_row': 3.0, 'first_number': 1, 'size': 46, 'rack_id': 1, 'notes': '', 'custom_fields': [], 'row': ''},
{'building': 'FRA2 (FRA11, EU9)', 'number_between_us': True, 'orientation': 'left', 'tags': [], 'numbering_start_from_bottom': 'yes', 'col_size': 1.0, 'rack_middle_option': 'Start at', 'asset_no': '', 'name': 'rack2', 'available_u': 42.0, 'rack_url': '/api/1.0/racks/2/', 'room': 'Room 007', 'start_col': 3.0, 'row_size': 1.0, 'start_row': 4.0, 'first_number': 1, 'size': 42, 'rack_id': 2, 'notes': '', 'custom_fields': [], 'row': ''},
{'building': 'FRA2 (FRA11, EU9)', 'number_between_us': True, 'orientation': 'left', 'tags': [], 'numbering_start_from_bottom': 'yes', 'col_size': 1.0, 'rack_middle_option': 'Start at', 'asset_no': '', 'name': 'rack3', 'available_u': 42.0, 'rack_url': '/api/1.0/racks/3/', 'room': 'Room 007', 'start_col': 3.0, 'row_size': 1.0, 'start_row': 5.0, 'first_number': 1, 'size': 42, 'rack_id': 3, 'notes': '', 'custom_fields': [], 'row': ''}
],

[
{'building': 'FRA2 (FRA11, EU9)', 'number_between_us': True, 'orientation': 'left', 'tags': [], 'numbering_start_from_bottom': 'yes', 'col_size': 1.0, 'rack_middle_option': 'Start at', 'asset_no': '', 'name': 'rack2', 'available_u': 42.0, 'rack_url': '/api/1.0/racks/2/', 'room': 'Room 007', 'start_col': 3.0, 'row_size': 1.0, 'start_row': 4.0, 'first_number': 1, 'size': 42, 'rack_id': 2, 'notes': '', 'custom_fields': [], 'row': ''},
{'building': 'FRA2 (FRA11, EU9)', 'number_between_us': True, 'orientation': 'left', 'tags': [], 'numbering_start_from_bottom': 'yes', 'col_size': 1.0, 'rack_middle_option': 'Start at', 'asset_no': '', 'name': 'rack3', 'available_u': 42.0, 'rack_url': '/api/1.0/racks/3/', 'room': 'Room 007', 'start_col': 3.0, 'row_size': 1.0, 'start_row': 5.0, 'first_number': 1, 'size': 42, 'rack_id': 3, 'notes': '', 'custom_fields': [], 'row': ''}
],
[
{'building': 'FRA2 (FRA11, EU9)', 'number_between_us': True, 'orientation': 'left', 'tags': [], 'numbering_start_from_bottom': 'yes', 'col_size': 1.0, 'rack_middle_option': 'Start at', 'asset_no': '', 'name': 'rack3', 'available_u': 42.0, 'rack_url': '/api/1.0/racks/3/', 'room': 'Room 007', 'start_col': 3.0, 'row_size': 1.0, 'start_row': 5.0, 'first_number': 1, 'size': 42, 'rack_id': 3, 'notes': '', 'custom_fields': [], 'row': ''}
],
[]
]