presto-main/src/main/java/io/prestosql/operator/aggregation/AggregationMetadata.java/AggregationMetadata/ParameterMetadata
class AggregationMetadata:        public ParameterMetadata(ParameterType parameterType, Type sqlType)
        {
            checkArgument((sqlType == null) == (parameterType == BLOCK_INDEX || parameterType == STATE),
                    "sqlType must be provided only for input channels");
            this.parameterType = parameterType;
            this.sqlType = sqlType;
        }