def []=(key, value)
      if not valid_type? value, @columns[key.to_sym].try(:[],:type)
        # Try to adapt the value
        adapter = get_adapter key, value
        raise ExtendModelAt::ArgumentError, "#{value.inspect} is not a valid type, expected #{@columns[key.to_sym][:type]}" if adapter.nil? # We can't adapt the value
        value = value.send adapter
      end
      @value[key.to_s] = value
      @model_manager.assign(key,value)
    end
def []=(key, value)
      if not valid_type? value, @columns[key.to_sym].try(:[],:type)
        # Try to adapt the value
        adapter = get_adapter key, value
        raise ExtendModelAt::ArgumentError, "#{value.inspect} is not a valid type, expected #{@columns[key.to_sym][:type]}" if adapter.nil? # We can't adapt the value
        value = value.send adapter
      end
      @value[key.to_s] = value
      @model_manager.assign(key,value)
    end
Set the value of the extended colum called [+key+] with the value [+value+]