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contracts...test.sol

pragma solidity >=0.7.0 <0.9.0;

/**
 * @title Ownership
 * check Ownership of nfts
 */
 
interface deployedContract {
    function totalSupply() external view returns (uint);
    function ownerOf(uint tokenId)external view returns (address);
    function balanceOf(address owner) external view returns(uint);
}
 
contract Ownership {
    
    function checkOwnership(address walletAddress, address contractAddress) public returns (uint[] memory){
        // getting total supply of the contract
        uint256 totalSupply = getTotalSupply(contractAddress);
        // getting total number of nfts owned by an address
        uint balance = getBalanceOf(contractAddress, walletAddress);
        // initializing an array with the size of total number of nfts owned by an address. 
        uint[] memory ids = new uint[](balance);
        // iterating through the total number of nfts present in contract
        for (uint id = 0; id <= totalSupply; totalSupply++) {
            // contracts whose owner is the given address are added to the array to be returned.
            if (walletAddress == deployedContract(contractAddress).ownerOf(id)) {
                for (uint index = 0; index < balance; index++) {
                    if (ids[index] == 0) {
                        ids[index] = id;
                        break;
                    }
                }
            } 
        }
        return ids; 
    }
    
    function getTotalSupply(address contractAddress) internal returns(uint256) {
        return deployedContract(contractAddress).totalSupply();
    }
    
    function getBalanceOf(address contractAddress, address owner) internal returns(uint256) {
        return deployedContract(contractAddress).balanceOf(owner);
    }
    
}