Review feedback

object_store/src/gcp/builder.rs

@@ -78,18 +78,17 @@ impl From<Error> for crate::Error {
     }
 }
 
-/// Configure a connection to Google Cloud Storage using the specified
-/// credentials.
+/// Configure a connection to Google Cloud Storage.
+///
+/// If no credentials are explicitly provided, they will be sourced
+/// from the environment as documented [here](https://cloud.google.com/docs/authentication/application-default-credentials).
 ///
 /// # Example
 /// ```
 /// # let BUCKET_NAME = "foo";
 /// # let SERVICE_ACCOUNT_PATH = "/tmp/foo.json";
 /// # use object_store::gcp::GoogleCloudStorageBuilder;
-/// let gcs = GoogleCloudStorageBuilder::new()
-///  .with_service_account_path(SERVICE_ACCOUNT_PATH)
-///  .with_bucket_name(BUCKET_NAME)
-///  .build();
+/// let gcs = GoogleCloudStorageBuilder::from_env().build();
 /// ```
 #[derive(Debug, Clone)]
 pub struct GoogleCloudStorageBuilder {
@@ -107,7 +106,7 @@ pub struct GoogleCloudStorageBuilder {
     retry_config: RetryConfig,
     /// Client options
     client_options: ClientOptions,
-    /// Credentials. Uses instance metadata credentials if not provided
+    /// Credentials
     credentials: Option<GcpCredentialProvider>,
 }
 
@@ -393,6 +392,7 @@ impl GoogleCloudStorageBuilder {
         self
     }
 
+    /// Set the credential provider overriding any other options
     pub fn with_credentials(mut self, credentials: GcpCredentialProvider) -> Self {
         self.credentials = Some(credentials);
         self