Crypto-BEP20-DevToken-Burn&Mint

  /**
  * @notice balanceOf will return the account balance for the given account
  */
  function balanceOf(address account) external view returns (uint256) {
    return _balances[account];
  } 
 
 /**
  * @notice mint will create tokens on the address inputted and then increase the total supply
  *
  * It will also emit an Transfer event, with sender set to zero address (adress(0))
  * 
  * Requires that the address that is recieveing the tokens is not zero address
  */
  function mint(address account, uint256 amount) public {
    require(account != address(0), "DevToken: cannot mint to zero address");

    // Increase total supply
    _totalSupply = _totalSupply + (amount);
    // Add amount to the account balance using the balance mapping
    _balances[account] = _balances[account] + amount;
    // Emit our event to log the action
    emit Transfer(address(0), account, amount);
  }
  /**
  * @notice burn will destroy tokens from an address inputted and then decrease total supply
  * An Transfer event will emit with receiever set to zero address
  * 
  * Requires 
  * - Account cannot be zero
  * - Account balance has to be bigger or equal to amount
  */
  function burn(address account, uint256 amount) public {
    require(account != address(0), "DevToken: cannot burn from zero address");
    require(_balances[account] >= amount, "DevToken: Cannot burn more than the account owns");

    // Remove the amount from the account balance
    _balances[account] = _balances[account] - amount;
    // Decrease totalSupply
    _totalSupply = _totalSupply - amount;
    // Emit event, use zero address as reciever
    emit Transfer(account, address(0), amount);
  }