human
Solve the following python programming problem given the following code:
def __init__(self, area, tab_scheme, default_tab_size, default_char = ' ') : 
    self.TAB_SIZE = None 
    self.CHAR = None 
    def set_tab_scheme(event) : 
        (ph, ext) = splitext (area.filename.lower ()) 
        (self.TAB_SIZE, self.CHAR) = tab_scheme.get (ext, (default_tab_size, default_char)) 
area.hook ((- 1), '<FocusIn>', tab_scheme) 
    area.hook ('INSERT', '<Tab>', (lambda event : self.insert_tab (event.widget))) 

    
    

    Fix the buggy line: area.hook ((- 1), '<FocusIn>', tab_scheme)
assistant
#Here is Python program to fix the buggy line: area.

area.hook ((- 1), '<FocusIn>', def set_tab_scheme()