Flattens component refs in a tree
    :param container: class
    :param expression: original expression
    :param instance_prefix: prefix for instance
    :return: flattened expression

def flatten_component_refs(
        container: ast.Class,
        expression: ast.Union[ast.ConnectClause, ast.AssignmentStatement, ast.ForStatement, ast.Symbol],
        instance_prefix: str) -> ast.Union[ast.ConnectClause, ast.AssignmentStatement, ast.ForStatement, ast.Symbol]:
    """
    Flattens component refs in a tree
    :param container: class
    :param expression: original expression
    :param instance_prefix: prefix for instance
    :return: flattened expression
    """

    expression_copy = copy.deepcopy(expression)

    w = TreeWalker()
    w.walk(ComponentRefFlattener(container, instance_prefix), expression_copy)

    return expression_copy