human
Solve the following python programming problem given the following code:
def get_case_hierarchy(case, type_info) : 
    def get_children(case, referenced_type = None, seen = None) : 
        seen = (seen or set ()) 
        ignore_types = type_info.get (case.type, { 
            
}).get ('ignore_relationship_types', []) 
        if (referenced_type and (referenced_type in ignore_types)) : 
            return None 
seen.add (case.case_id) 
        children = [get_children (i.referenced_case, i.referenced_type, seen) for i in case.reverse_indices if (i.referenced_id not in seen)] 
        children = [c for c in children if (c is not None)] 
        descendant_types = [] 
        for c in children : 
            descendant_types.extend (c ['descendant_types']) 
descendant_types = list (set (descendant_types)) 
        children = sorted (children, key = partial (sortkey, type_info = type_info)) 
        for c in children : 
            if (not hasattr (c ['case'], 'treetable_parent_node_id')) : 
                c ['case'].treetable_parent_node_id = case.case_id 
child_cases = [] 
        for c in children : 
            child_cases.extend (c ['case_list']) 
return { 
            'case' : case, 
            'child_cases' : children, 
            'descendant_types' : list (set ((descendant_types + [c ['case'].type for c in children]))), 
            'case_list' : ([case] + child_cases), 
} 
return get_children (type_info) 

    
    

    Fix the buggy line: return get_children (type_info)
assistant
#Here is Python program to fix the buggy line: return get_children (type_info)
.

return get_children (case)