code: def set_chars(self, array):
          
  
          if len(array) != 4:
              raise ArraySizeError("array should contain 4 characters")
          array = [ x[:1] for x in [ str(s) for s in array ] ]
          (self._char_horiz, self._char_vert,
              self._char_corner, self._char_header) = array
          return self
docs: Set the characters used to draw lines between rows and columns
  
          - the array should contain 4 fields:
  
              [horizontal, vertical, corner, header]
  
          - default is set to:
  
              ['-', '|', '+', '=']