NFT20Factory functions to provide mappings between NFT contract addresses and NFT20 pairs for trading those assets.
This contract is an AdminUpgradeabilityProxy contract currently deployed at
0x0f4676178b5c53Ae0a655f1B19A96387E4b8B5f2on mainnet Ethereum.
The currently deployed version is NFT20FactoryV3 at
0xf39b0F846f967895DB4c31B6b62d2BE3F5Af8454on mainnet Ethereum.
Contract address for an ERC721/ERC1155.
This method method returns the value of
uint256 counter, which represents the number of NFT20Pairs currently tracked by the factory.