Function init 

pub fn init(api_key: impl Into<String>) -> Result<()>

Initialize the global FRED client with an API key.

Must be called once before series. Subsequent calls return an error.

Arguments

• api_key - Your FRED API key (free at https://fred.stlouisfed.org/docs/api/api_key.html)

Errors

Returns FinanceError::InvalidParameter if already initialized.