AggregateExpression compileAggregateExpr( Context context, Node parent, Node callNode ) throws DataException
protected AggregateExpression compileAggregateExpr( Context context, Node parent, Node callNode ) throws DataException
	AggregateExpression compileAggregateExpr( Context context, Node parent, Node callNode ) throws DataException	{		assert( callNode.getType() == Token.CALL );				IAggregation aggregation = getAggregationFunction( callNode );		// not an aggregation function being called, then it's considered 		// a complex expression		if( aggregation == null )			return null;				AggregateExpression aggregateExpression = 			new AggregateExpression( aggregation );				extractArguments( context, aggregateExpression, callNode );		replaceAggregateNode( aggregateExpression, parent, callNode );				return aggregateExpression;	}