human
Solve the following python programming problem given the following code:
def concatenate_adjacent_comments(self) : 
    '
        Merges any comments that are adjacent.
        ' 
    def concatenate(region1, region2) : 
        return region1.cover (region2) 
def is_adjacent(region1, region2) : 
        region_inbetween = Region (region1.end (), region2.begin ()) 
        return (len (self.view.substr (region_inbetween).strip ()) == 0) 
concatenated_comments = [] 
    for (prev_comment, comment) in previous_and_current (self.comments) : 
        concatenated_comment = None 
        if (prev_comment and is_adjacent (prev_comment, comment)) : 
            concatenated_comment = concatenate (concatenated_comments.pop (), comment) 
concatenated_comments.append ((concatenated_comment or concatenated_comments)) 
self.comments = concatenated_comments 

    
    

    Fix the buggy line: concatenated_comments.append ((concatenated_comment or concatenated_comments))
assistant
#Here is Python code to fix the buggy line: concatenated_comments.

concatenated_comments.append ((concatenated_comment or comment))