Issue with groovy expresssion in ADF 12.1.3

I was trying to define a groovy expression for creating a sequence for one of my entity object attribute.

(new oracle.jbo.server.SequenceImpl("SEQ_NAME", adf.object.getDBTransaction())).getSequenceNumber()

But while trying to create a new record using BC Tester I am getting the following exception.

General error during semantic analysis: JBO-25152: Calling the constructor for class oracle.jbo.server.SequenceImpl is not permitted.

oracle.jbo.ExprSecurityException: JBO-25152: Calling the constructor for class oracle.jbo.server.SequenceImpl is not permitted.

After debugging for some time, I have found a resolution for this. While defining a groovy expression for an entity object attribute, the source code is generated as below.

<TransientExpression trustMode="untrusted"><![CDATA[(new oracle.jbo.server.SequenceImpl("SEQ_NAME", adf.object.getDBTransaction())).getSequenceNumber()]]></TransientExpression>

In order to resolve the above issue we need to make the trustMode attribute to trusted or remove the attribute trustMode as the default value for this attribute is trusted. 

<TransientExpression><![CDATA[(new oracle.jbo.server.SequenceImpl("SEQ_NAME", adf.object.getDBTransaction())).getSequenceNumber()]]></TransientExpression>