def delta_account_item(address, param, value)
      new_value = get_account_item(address, param) + value
      return false if new_value < 0

      set_account_item(address, param, new_value % 2**256)
      true
    end
def delta_account_item(address, param, value)
      new_value = get_account_item(address, param) + value
      return false if new_value < 0

      set_account_item(address, param, new_value % 2**256)
      true
    end
Add a value to an account item.

 If the resulting value would be negative, it is left unchanged and
 `false` is returned.

 @param address [String] the address of the account (binary or hex string)
 @param param [Symbol] the parameter to increase or decrease (`:nonce`,
   `:balance`, `:storage`, or `:code`)
 @param value [Integer] can be positive or negative

 @return [Bool] `true` if the operation was successful, `false` if not