First test kinda working

simulator/src/lib.rs

@@ -0,0 +1,12 @@
+pub mod client;
+pub mod emitters;
+pub mod profile;
+
+/// Install rustls' default crypto provider. Idempotent: safe to call from
+/// every test, every binary entry, and the substrate process. The `aws_lc_rs`
+/// provider matches what the substrate installs in `main.rs`.
+pub fn install_crypto_provider() {
+    // Returns Err if a provider is already installed; that's the expected
+    // case in any process that's already booted substrate or a sibling test.
+    let _ = rustls::crypto::aws_lc_rs::default_provider().install_default();
+}