in lib/eventstream_rpc.ts [1101:1112]
function validateShape(model: EventstreamRpcServiceModel, shapeName: string, shape: any) : void {
if (!shape) {
throw createRpcError(RpcErrorType.ValidationError, `Shape of type '${shapeName}' is undefined`);
}
let validator = model.validators.get(shapeName);
if (!validator) {
throw createRpcError(RpcErrorType.ValidationError, `No shape named '${shapeName}' exists in the service model`);
}
validator(shape);
}