@Override
  public GenericUDAFEvaluator getEvaluator(TypeInfo[] info) 
    throws SemanticException {
    throw new SemanticException(
          "This UDAF does not support the deprecated getEvaluator() method.");
  }
An abstract class to help facilitate existing implementations of
<pre>GenericUDAFResolver</pre> to migrate towards the newly introduced
interface {@link GenericUDAFResolver2}. This class provides a default
implementation of this new API and in turn calls
the existing API {@link GenericUDAFResolver#getEvaluator(TypeInfo[])} by
ignoring the extra parameter information available via the
<pre>GenericUDAFParameterInfo</pre> interface.
ql/src/java/org/apache/hadoop/hive/ql/udf/generic/AbstractGenericUDAFResolver.java