def __call__(self, node, parent):
if (not self.done):<EOL><INDENT>if (node == self.target):<EOL><INDENT>self.done = True<EOL><DEDENT>return True<EOL><DEDENT>else:<EOL><INDENT>return False<EOL><DEDENT>
Decide if the given node should be included in the search process.

@type  node: node
@param node: Given node.

@type  parent: node
@param parent: Given node's parent in the spanning tree.

@rtype: boolean
@return: Whether the given node should be included in the search process.