function table.arrayToMap(tab)
  	local len = #tab
  	local result = {}
  	for i = 1, len, 2 do
  		result[tab[i]] = tab[i + 1]
  	end
  	return result

  end
  
  function table.clear(tab)
  	for k, _ in pairs(tab) do
  		tab[k] = nil
  	end

  end
  
  function table.numbers(tab)
  	local count = 0
  	for k, _ in pairs(tab) do
  		count = count + 1
  	end
  	return count

  end