Crypto-BEP20-DevToken-Transfer

  /**
  * @notice transfer is used to transfer funds from the sender to the recipient
  * This function is only callable from outside the contract. For internal usage see 
  * _transfer
  *
  * Requires
  * - Caller cannot be zero
  * - Caller must have a balance = or bigger than amount
  *
   */
  function transfer(address recipient, uint256 amount) external returns (bool) {
    _transfer(msg.sender, recipient, amount);
    return true;
  }
  /**
  * @notice _transfer is used for internal transfers
  * 
  * Events
  * - Transfer
  * 
  * Requires
  *  - Sender cannot be zero
  *  - recipient cannot be zero 
  *  - sender balance most be = or bigger than amount
   */
  function _transfer(address sender, address recipient, uint256 amount) internal {
    require(sender != address(0), "DevToken: transfer from zero address");
    require(recipient != address(0), "DevToken: transfer to zero address");
    require(_balances[sender] >= amount, "DevToken: cant transfer more than your account holds");

    _balances[sender] = _balances[sender] - amount;
    _balances[recipient] = _balances[recipient] + amount;

    emit Transfer(sender, recipient, amount);
  }