{
try
{
Field f = ExpressionDocumenter.class.getDeclaredField( "EXPRESSION_ROOTS" );
f.setAccessible( true );
String[] value = (String[]) f.get( new ExpressionDocumenter() );
if ( value == null )
{
throw new MojoExecutionException( "org.apache.maven.usability.plugin.ExpressionDocumenter#"
+ "EXPRESSION_ROOTS has no value." );
}