def __init__(self, node_list=None, node_value_list=None, relation_list=None, attribute_list=None):
<EOL>if node_list is None:<EOL><INDENT>self.nodes = []<EOL>self.root = None<EOL><DEDENT>else:<EOL><INDENT>self.nodes = node_list[:]<EOL>if len(node_list) != <NUM_LIT:0>:<EOL><INDENT>self.root = node_list[<NUM_LIT:0>]<EOL><DEDENT>else:<EOL><INDENT>self.root = None<EOL><DEDENT><DEDENT>if node_value_list is None:<EOL><INDENT>self.node_values = []<EOL><DEDENT>else:<EOL><INDENT>self.node_values = node_value_list[:]<EOL><DEDENT>if relation_list is None:<EOL><INDENT>self.relations = []<EOL><DEDENT>else:<EOL><INDENT>self.relations = relation_list[:]<EOL><DEDENT>if attribute_list is None:<EOL><INDENT>self.attributes = []<EOL><DEDENT>else:<EOL><INDENT>self.attributes = attribute_list[:]<EOL><DEDENT>
node_list: names of nodes in AMR graph, e.g. "a11", "n"
node_value_list: values of nodes in AMR graph, e.g. "group" for a node named "g"
relation_list: list of relations between two nodes
attribute_list: list of attributes (links between one node and one constant value)