pub fn message_start_event(
id: String,
model: String,
service_tier: BetaServiceTier,
input_tokens: u64,
cached_input_tokens: u64,
) -> ClaudeStreamEventpub fn message_start_event(
id: String,
model: String,
service_tier: BetaServiceTier,
input_tokens: u64,
cached_input_tokens: u64,
) -> ClaudeStreamEvent