Function build_rpc_op_resolver_with_prefix 

pub fn build_rpc_op_resolver_with_prefix(
    prefix: &str,
    ops: &'static [OpDescriptor],
) -> impl Fn(&Request<Body>) + Send + Sync + use<>

build_rpc_op_resolver for a router mounted under prefix, e.g. build_rpc_op_resolver_with_prefix("/api", OPS) to match Router::nest("/api", router).

Same forgiving-spelling / strict-boundary rules as the REST twin, and the same use<>: the prefix may be a runtime String.