public ModifyDBInstanceRequest withCACertificateIdentifier(String cACertificateIdentifier) {
        setCACertificateIdentifier(cACertificateIdentifier);
        return this;
    }
<p>
Indicates the certificate that needs to be associated with the instance.
</p>

@param cACertificateIdentifier
       Indicates the certificate that needs to be associated with the instance.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-docdb/src/main/java/com/amazonaws/services/docdb/model/ModifyDBInstanceRequest.java