 maxPer is integer, then it treats maxPer is expressed in count.
Otherwise, it will be treated as float.
Example: maxPer=10 will be treated as integer, while maxPer=10.0 will be treated as float</p>
</dd>
<dt>sep<span class="classifier">str</span></dt><dd><p>This variable is used to distinguish items from one another in a transaction. The default seperator is tab space or         .
However, the users can override their default separator.</p>
</dd>
<dt>memoryUSS<span class="classifier">float</span></dt><dd><