code: def p_block_empty(self, p):
          'block : BEGIN END'
          p[0] = Block((), lineno=p.lineno(1))
          p.set_lineno(0, p.lineno(1)f p_block_empty(self, p):
          'block : BEGIN END'
          p[0] = Block((), lineno=p.lineno(1))
          p.set_lineno(0, p.lineno(1))
docs: block : BEGIN END