@java.lang.Override
    public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
      if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(clientId_)) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 1, clientId_);
      }
      if (((bitField0_ & 0x00000001) != 0)) {
        output.writeMessage(2, getClientSecret());
      }
      if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(tenantId_)) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 3, tenantId_);
      }
      if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(sharepointSiteName_)) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 4, sharepointSiteName_);
      }
      if (folderSourceCase_ == 5) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 5, folderSource_);
      }
      if (folderSourceCase_ == 6) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 6, folderSource_);
      }
      if (driveSourceCase_ == 7) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 7, driveSource_);
      }
      if (driveSourceCase_ == 8) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 8, driveSource_);
      }
      if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(fileId_)) {
        com.google.protobuf.GeneratedMessageV3.writeString(output, 9, fileId_);
      }
      getUnknownFields().writeTo(output);
    }
<pre>
Output only. The SharePoint file id. Output only.
</pre>

<code>string file_id = 9 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

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