def get_child_node_or_default(self, name, default=None):
try:<EOL><INDENT>return self._nodes[name]<EOL><DEDENT>except KeyError:<EOL><INDENT>return default<EOL><DEDENT>
Retrieve child node if it exist or return a default value.

Args:
    name (str): Name of the node to retrieve.
    default: Default value to return if no named child node is found.