Function push_if_node_or_array 

pub fn push_if_node_or_array<'a>(
    tree: &'a Value,
    key: &str,
    stack: &mut Vec<&'a Value>,
)

Push a JSON value onto stack if the field key is an object or array.

Used during AST walks that iterate over child nodes without full typed deserialization. Objects are pushed as-is; arrays are flattened so each element is pushed individually.