@java.lang.Override
      public com.google.protobuf.ByteString getDriveIdBytes() {
        java.lang.Object ref = "";
        if (driveSourceCase_ == 8) {
          ref = driveSource_;
        }
        if (ref instanceof String) {
          com.google.protobuf.ByteString b =
              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
          if (driveSourceCase_ == 8) {
            driveSource_ = b;
          }
          return b;
        } else {
          return (com.google.protobuf.ByteString) ref;
        }
      }
<pre>
The ID of the drive to download from.
</pre>

<code>string drive_id = 8;</code>

@return The bytes for driveId.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/SharePointSources.java