Solidity sink contract

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.7;

contract Contract {
  uint internal balance;
  address internal owner;

  constructor() {
    owner = msg.sender;
  }

  receive() payable external {
    balance += msg.value;
  }

  function get_balance() public view returns(uint) {
    return balance;
  }
}