public Builder setRoleArn(java.lang.String value) {
        if (value == null) {
          throw new NullPointerException();
        }
        roleArn_ = value;
        bitField0_ |= 0x00000008;
        onChanged();
        return this;
      }
<pre>
The Amazon Resource Name (ARN) of the role to support temporary
credentials via `AssumeRoleWithWebIdentity`. For more information about
ARNs, see [IAM
ARNs](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_identifiers.html#identifiers-arns).

When a role ARN is provided, Transfer Service fetches temporary
credentials for the session using a `AssumeRoleWithWebIdentity` call for
the provided role using the
[GoogleServiceAccount][google.storagetransfer.v1.GoogleServiceAccount] for
this project.
</pre>

<code>string role_arn = 4;</code>

@param value The roleArn to set.
@return This builder for chaining.
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java