usestd::time::Duration;/// Common interface that all provider configs must implement.
////// This lets generic code introspect
/// provider configuration without knowing the concrete type.
pubtraitProviderConfig{/// Base URL of the provider API.
fnbase_url(&self)->&str;/// Model identifier to use for requests.
fnmodel(&self)->&str;/// Optional API key for authentication.
fnapi_key(&self)->Option<&str>;/// Request timeout duration.
fntimeout(&self)-> Duration;}