def class_names(self, nodes):
names = []<EOL>for node in nodes:<EOL><INDENT>if isinstance(node, astroid.Instance):<EOL><INDENT>node = node._proxied<EOL><DEDENT>if (<EOL>isinstance(node, astroid.ClassDef)<EOL>and hasattr(node, "<STR_LIT:name>")<EOL>and not self.has_node(node)<EOL>):<EOL><INDENT>if node.name not in names:<EOL><INDENT>node_name = node.name<EOL>names.append(node_name)<EOL><DEDENT><DEDENT><DEDENT>return names<EOL>
return class names if needed in diagram