对于含有 block 参数的 lambda,递归要像下面这样写吗?
base = 10
lambda_x = ->(&block_x) {
  if base == 0
    return
  else
    base -= 1
    puts 'some operations...'
    block_x.call
    lambda_x.call do
      puts "I'm in block_x"
    end
  end
}
lambda_x.call do
  puts "I'm in block_x"
end