groovy exprsssion-filter

Looking at mule.xsd 2.1.0 it looks like groovy is not a valid evaluator attribute value in contrast to the example given in
http://www.mulesource.org/display/MULE2USER/Using+Expressions#UsingExpressions-UsingExpressionFilters.

Was this dropped in mule 2.1.0 or is this just an oversight?

Steve