Code shared from the Rust Playground

playground.rs

use serde::Serialize;

pub struct CreateBuilder {
    collection: Option<String>,
    data: String
}

impl<S: Serialize> From<S> for CreateBuilder {
    fn from(data: S) -> Self {
        Self {
            collection: None,
            data: serde_json::to_string(&data).unwrap(),
        }
    }
}

impl<S: Serialize> From<(&str, S)> for CreateBuilder {
    fn from((collection, data): (&str, S)) -> Self {
        Self {
            collection: Some(collection.to_string()),
            data: serde_json::to_string(&data).unwrap(),
        }
    }
}