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fundme.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import {newfund} from "./test.sol";
contract fundme{
    using newfund for uint;
    address public owner;
    uint minimunUsd = 5e18;
    address[] public funders;
    mapping(address funder => uint amountfunded) public valueofthefund;
    
    constructor(){
    owner = msg.sender;
   }


    //for a Tx to work it must add payable 
    function fund () public payable {

        //msg.value.getconversion();

        //the require checks for the sender of the value to meet a check 
        //require (getconversion(msg.value) > minimunUsd, "Not enough ETH!!!");
        require (msg.value.getconversion() <= minimunUsd);
        funders.push(msg.sender);
        valueofthefund[msg.sender] += msg.value;
    }

    function withdraw () public onlyowner {
        for (uint funderindex = 0; funderindex < funders.length; funderindex++){
            address funder = funders[funderindex];
            valueofthefund[funder] = 0;
        }
        funders = new address [] (0);
        // transfer using paybale since we are transfering to another address
        payable (msg.sender).transfer(address(this).balance);

        //send 
         bool sendSucess = payable (msg.sender).send(address(this).balance);
         require (sendSucess, "Failed to send transaction!!!");

         //call
         (bool success, ) = payable (msg.sender).call{value: address(this).balance}("");
         require (success, "call failed!!!");
        
    }

    modifier onlyowner(){
        // you can put the _; above the require or below to show which function should be run first!!
        require (msg.sender == owner, "Must be the owner!!!");
        _;
    }

   
}

test.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;
import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

library newfund{

    function getUSD() internal view returns (uint) {
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x694AA1769357215DE4FAC081bf1f309aDC325306);
        (,int256 price,,,) = priceFeed.latestRoundData();
        return uint (price *1e18);
        //0x694AA1769357215DE4FAC081bf1f309aDC325306
    }

    function getconversion (uint ethamount) internal view returns (uint) {
        uint iniprice = getUSD();
        uint ethamountUSD = (iniprice * ethamount) /1e18;
        return ethamountUSD;
    }

    
}