private boolean getEvaluateWhen(Map<String, String> requestInfoProperties) {
    return (requestInfoProperties != null) && "true".equalsIgnoreCase(requestInfoProperties.get(DIRECTIVE_EVALUATE_WHEN_CLAUSE));
  }
Determine if <code>when</code> chauses should be evaluated or not.
<p>
This is determined by the existance and value of the <code>evaluate_when</code> directive.
If it exists and is set to "true", then <code>when</code> clauses should be evaluated, else
they should not.

@param requestInfoProperties a map a request info properties
@return true if <code>when</code> clauses are to be evaluted; false otherwise
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/ClusterKerberosDescriptorResourceProvider.java