#NEWLINE# def add_node( self , node ) : #NEWLINE# #INDENT# "\n        Add given node to the hypergraph.\n        \n        @attention: While nodes can be of any type, it's strongly recommended to use only numbers\n        and single-line strings as node identifiers if you intend to use write().\n\n        @type  node: node\n        @param node: Node identifier.\n        " #NEWLINE# if ( not ( node in self . node_links ) ) : #NEWLINE# #INDENT# self . node_links [ node ] = [ ] #NEWLINE# self . node_attr [ node ] = [ ] #NEWLINE# self . graph . add_node ( ( self , 'n' ) ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# raise AdditionError ( ( 'Node %s already in graph' % node ) )