parameters: (self, other_line)
docstring: Adds a reference to an alternative line from another civ
          to this line.
docstring_summary: Adds a reference to an alternative line from another civ
          to this line.
docstring_tokens: Adds a reference to an alternative line from another civ to this line .
function: def add_civ_line(self, other_line):
          """
          Adds a reference to an alternative line from another civ
          to this line.
          """
          other_civ_id = other_line.get_civ_id()
          self.civ_lines[other_civ_id] = other_line
function_tokens: def add_civ_line ( self , other_line ) : other_civ_id = other_line . get_civ_id ( ) self . civ_lines [ other_civ_id ] = other_line