mark contract/utils functions as private in JSDoc

src/contract/utils.ts

@@ -11,6 +11,7 @@ export const DEFAULT_TIMEOUT = 5 * 60;
 /**
  * Keep calling a `fn` for `timeoutInSeconds` seconds, if `keepWaitingIf` is
  * true. Returns an array of all attempts to call the function.
+ * @private
  */
 export async function withExponentialBackoff<T>(
   /** Function to call repeatedly */
@@ -92,6 +93,7 @@ export const contractErrorPattern = /Error\(Contract, #(\d+)\)/;
 
 /**
  * A TypeScript type guard that checks if an object has a `toString` method.
+ * @private
  */
 export function implementsToString(
   /** some object that may or may not have a `toString` method */
@@ -102,6 +104,7 @@ export function implementsToString(
 
 /**
  * Reads a binary stream of ScSpecEntries into an array for processing by ContractSpec
+ * @private
  */
 export function processSpecEntryStream(buffer: Buffer) {
   const reader = new cereal.XdrReader(buffer);