# how a new segment should look like?
```
/// ST - Transaction Set Header
#[derive(Serialize, Deserialize, Clone, Default, Debug, Validate, PartialEq, Eq)]
pub struct ST {
#[serde(rename = "01")]
pub _01: String,
#[serde(rename = "02")]
pub _02: String,
#[serde(rename = "03")]
pub _03: Option<String>,
}
```