<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def grok_if_node(element, default_vars):
 """Properly parses a If element"""

    if isinstance(element.test, jinja2.nodes.Filter) and \
       element.test.name == 'default':
        default_vars.append(element.test.node.name)

    return default_vars + grok_vars(element)