class NodeLabels:
  TYPE = 'node_type'
  CONNECTION_TYPE = 'connection_type'
  EQUIPMENT = 'equipment'
  # igraph require 'label', do not change the string value
  LABEL = 'label'
  # igraph require 'color', do not change the string value
  COLOR = 'color'
  # igraph require 'name', do not change the string value
  NAME = 'name'