pub fn default(address: Address) -> Self {
        let default_name = format!("ERC20-{:x}", address);
        Self {
            name: default_name.clone(),
            symbol: default_name,
            decimals: 18,
        }
    }
Creates a default representation of token data, which will be used for tokens that have
not known metadata.
core/lib/types/src/tokens.rs